| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Simplified MAC Kernel (smack) security module |
| * |
| * This file contains the smack hook function implementations. |
| * |
| * Authors: |
| * Casey Schaufler <casey@schaufler-ca.com> |
| * Jarkko Sakkinen <jarkko.sakkinen@intel.com> |
| * |
| * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> |
| * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. |
| * Paul Moore <paul@paul-moore.com> |
| * Copyright (C) 2010 Nokia Corporation |
| * Copyright (C) 2011 Intel Corporation. |
| */ |
| |
| #include <linux/xattr.h> |
| #include <linux/pagemap.h> |
| #include <linux/mount.h> |
| #include <linux/stat.h> |
| #include <linux/kd.h> |
| #include <asm/ioctls.h> |
| #include <linux/ip.h> |
| #include <linux/tcp.h> |
| #include <linux/udp.h> |
| #include <linux/dccp.h> |
| #include <linux/icmpv6.h> |
| #include <linux/slab.h> |
| #include <linux/mutex.h> |
| #include <net/cipso_ipv4.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <linux/audit.h> |
| #include <linux/magic.h> |
| #include <linux/dcache.h> |
| #include <linux/personality.h> |
| #include <linux/msg.h> |
| #include <linux/shm.h> |
| #include <linux/binfmts.h> |
| #include <linux/parser.h> |
| #include <linux/fs_context.h> |
| #include <linux/fs_parser.h> |
| #include <linux/watch_queue.h> |
| #include <linux/io_uring.h> |
| #include "smack.h" |
| |
| #define TRANS_TRUE "TRUE" |
| #define TRANS_TRUE_SIZE 4 |
| |
| #define SMK_CONNECTING 0 |
| #define SMK_RECEIVING 1 |
| #define SMK_SENDING 2 |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| static DEFINE_MUTEX(smack_ipv6_lock); |
| static LIST_HEAD(smk_ipv6_port_list); |
| #endif |
| struct kmem_cache *smack_rule_cache; |
| int smack_enabled __initdata; |
| |
| #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s} |
| static struct { |
| const char *name; |
| int len; |
| int opt; |
| } smk_mount_opts[] = { |
| {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault}, |
| A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute) |
| }; |
| #undef A |
| |
| static int match_opt_prefix(char *s, int l, char **arg) |
| { |
| int i; |
| |
| for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) { |
| size_t len = smk_mount_opts[i].len; |
| if (len > l || memcmp(s, smk_mount_opts[i].name, len)) |
| continue; |
| if (len == l || s[len] != '=') |
| continue; |
| *arg = s + len + 1; |
| return smk_mount_opts[i].opt; |
| } |
| return Opt_error; |
| } |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static char *smk_bu_mess[] = { |
| "Bringup Error", /* Unused */ |
| "Bringup", /* SMACK_BRINGUP_ALLOW */ |
| "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */ |
| "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */ |
| }; |
| |
| static void smk_bu_mode(int mode, char *s) |
| { |
| int i = 0; |
| |
| if (mode & MAY_READ) |
| s[i++] = 'r'; |
| if (mode & MAY_WRITE) |
| s[i++] = 'w'; |
| if (mode & MAY_EXEC) |
| s[i++] = 'x'; |
| if (mode & MAY_APPEND) |
| s[i++] = 'a'; |
| if (mode & MAY_TRANSMUTE) |
| s[i++] = 't'; |
| if (mode & MAY_LOCK) |
| s[i++] = 'l'; |
| if (i == 0) |
| s[i++] = '-'; |
| s[i] = '\0'; |
| } |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_note(char *note, struct smack_known *sskp, |
| struct smack_known *oskp, int mode, int rc) |
| { |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc], |
| sskp->smk_known, oskp->smk_known, acc, note); |
| return 0; |
| } |
| #else |
| #define smk_bu_note(note, sskp, oskp, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_current(char *note, struct smack_known *oskp, |
| int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc], |
| tsp->smk_task->smk_known, oskp->smk_known, |
| acc, current->comm, note); |
| return 0; |
| } |
| #else |
| #define smk_bu_current(note, oskp, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_task(struct task_struct *otp, int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct smack_known *smk_task = smk_of_task_struct_obj(otp); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc], |
| tsp->smk_task->smk_known, smk_task->smk_known, acc, |
| current->comm, otp->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_task(otp, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_inode(struct inode *inode, int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct inode_smack *isp = smack_inode(inode); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (isp->smk_flags & SMK_INODE_IMPURE) |
| pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| if (rc == SMACK_UNCONFINED_SUBJECT && |
| (mode & (MAY_WRITE | MAY_APPEND))) |
| isp->smk_flags |= SMK_INODE_IMPURE; |
| |
| smk_bu_mode(mode, acc); |
| |
| pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc], |
| tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc, |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_inode(inode, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_file(struct file *file, int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct smack_known *sskp = tsp->smk_task; |
| struct inode *inode = file_inode(file); |
| struct inode_smack *isp = smack_inode(inode); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (isp->smk_flags & SMK_INODE_IMPURE) |
| pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], |
| sskp->smk_known, smk_of_inode(inode)->smk_known, acc, |
| inode->i_sb->s_id, inode->i_ino, file, |
| current->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_file(file, mode, RC) (RC) |
| #endif |
| |
| #ifdef CONFIG_SECURITY_SMACK_BRINGUP |
| static int smk_bu_credfile(const struct cred *cred, struct file *file, |
| int mode, int rc) |
| { |
| struct task_smack *tsp = smack_cred(cred); |
| struct smack_known *sskp = tsp->smk_task; |
| struct inode *inode = file_inode(file); |
| struct inode_smack *isp = smack_inode(inode); |
| char acc[SMK_NUM_ACCESS_TYPE + 1]; |
| |
| if (isp->smk_flags & SMK_INODE_IMPURE) |
| pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n", |
| inode->i_sb->s_id, inode->i_ino, current->comm); |
| |
| if (rc <= 0) |
| return rc; |
| if (rc > SMACK_UNCONFINED_OBJECT) |
| rc = 0; |
| |
| smk_bu_mode(mode, acc); |
| pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc], |
| sskp->smk_known, smk_of_inode(inode)->smk_known, acc, |
| inode->i_sb->s_id, inode->i_ino, file, |
| current->comm); |
| return 0; |
| } |
| #else |
| #define smk_bu_credfile(cred, file, mode, RC) (RC) |
| #endif |
| |
| /** |
| * smk_fetch - Fetch the smack label from a file. |
| * @name: type of the label (attribute) |
| * @ip: a pointer to the inode |
| * @dp: a pointer to the dentry |
| * |
| * Returns a pointer to the master list entry for the Smack label, |
| * NULL if there was no label to fetch, or an error code. |
| */ |
| static struct smack_known *smk_fetch(const char *name, struct inode *ip, |
| struct dentry *dp) |
| { |
| int rc; |
| char *buffer; |
| struct smack_known *skp = NULL; |
| |
| if (!(ip->i_opflags & IOP_XATTR)) |
| return ERR_PTR(-EOPNOTSUPP); |
| |
| buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS); |
| if (buffer == NULL) |
| return ERR_PTR(-ENOMEM); |
| |
| rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL); |
| if (rc < 0) |
| skp = ERR_PTR(rc); |
| else if (rc == 0) |
| skp = NULL; |
| else |
| skp = smk_import_entry(buffer, rc); |
| |
| kfree(buffer); |
| |
| return skp; |
| } |
| |
| /** |
| * init_inode_smack - initialize an inode security blob |
| * @inode: inode to extract the info from |
| * @skp: a pointer to the Smack label entry to use in the blob |
| * |
| */ |
| static void init_inode_smack(struct inode *inode, struct smack_known *skp) |
| { |
| struct inode_smack *isp = smack_inode(inode); |
| |
| isp->smk_inode = skp; |
| isp->smk_flags = 0; |
| } |
| |
| /** |
| * init_task_smack - initialize a task security blob |
| * @tsp: blob to initialize |
| * @task: a pointer to the Smack label for the running task |
| * @forked: a pointer to the Smack label for the forked task |
| * |
| */ |
| static void init_task_smack(struct task_smack *tsp, struct smack_known *task, |
| struct smack_known *forked) |
| { |
| tsp->smk_task = task; |
| tsp->smk_forked = forked; |
| INIT_LIST_HEAD(&tsp->smk_rules); |
| INIT_LIST_HEAD(&tsp->smk_relabel); |
| mutex_init(&tsp->smk_rules_lock); |
| } |
| |
| /** |
| * smk_copy_rules - copy a rule set |
| * @nhead: new rules header pointer |
| * @ohead: old rules header pointer |
| * @gfp: type of the memory for the allocation |
| * |
| * Returns 0 on success, -ENOMEM on error |
| */ |
| static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead, |
| gfp_t gfp) |
| { |
| struct smack_rule *nrp; |
| struct smack_rule *orp; |
| int rc = 0; |
| |
| list_for_each_entry_rcu(orp, ohead, list) { |
| nrp = kmem_cache_zalloc(smack_rule_cache, gfp); |
| if (nrp == NULL) { |
| rc = -ENOMEM; |
| break; |
| } |
| *nrp = *orp; |
| list_add_rcu(&nrp->list, nhead); |
| } |
| return rc; |
| } |
| |
| /** |
| * smk_copy_relabel - copy smk_relabel labels list |
| * @nhead: new rules header pointer |
| * @ohead: old rules header pointer |
| * @gfp: type of the memory for the allocation |
| * |
| * Returns 0 on success, -ENOMEM on error |
| */ |
| static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead, |
| gfp_t gfp) |
| { |
| struct smack_known_list_elem *nklep; |
| struct smack_known_list_elem *oklep; |
| |
| list_for_each_entry(oklep, ohead, list) { |
| nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp); |
| if (nklep == NULL) { |
| smk_destroy_label_list(nhead); |
| return -ENOMEM; |
| } |
| nklep->smk_label = oklep->smk_label; |
| list_add(&nklep->list, nhead); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_* |
| * @mode: input mode in form of PTRACE_MODE_* |
| * |
| * Returns a converted MAY_* mode usable by smack rules |
| */ |
| static inline unsigned int smk_ptrace_mode(unsigned int mode) |
| { |
| if (mode & PTRACE_MODE_ATTACH) |
| return MAY_READWRITE; |
| if (mode & PTRACE_MODE_READ) |
| return MAY_READ; |
| |
| return 0; |
| } |
| |
| /** |
| * smk_ptrace_rule_check - helper for ptrace access |
| * @tracer: tracer process |
| * @tracee_known: label entry of the process that's about to be traced |
| * @mode: ptrace attachment mode (PTRACE_MODE_*) |
| * @func: name of the function that called us, used for audit |
| * |
| * Returns 0 on access granted, -error on error |
| */ |
| static int smk_ptrace_rule_check(struct task_struct *tracer, |
| struct smack_known *tracee_known, |
| unsigned int mode, const char *func) |
| { |
| int rc; |
| struct smk_audit_info ad, *saip = NULL; |
| struct task_smack *tsp; |
| struct smack_known *tracer_known; |
| const struct cred *tracercred; |
| |
| if ((mode & PTRACE_MODE_NOAUDIT) == 0) { |
| smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, tracer); |
| saip = &ad; |
| } |
| |
| rcu_read_lock(); |
| tracercred = __task_cred(tracer); |
| tsp = smack_cred(tracercred); |
| tracer_known = smk_of_task(tsp); |
| |
| if ((mode & PTRACE_MODE_ATTACH) && |
| (smack_ptrace_rule == SMACK_PTRACE_EXACT || |
| smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) { |
| if (tracer_known->smk_known == tracee_known->smk_known) |
| rc = 0; |
| else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN) |
| rc = -EACCES; |
| else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred)) |
| rc = 0; |
| else |
| rc = -EACCES; |
| |
| if (saip) |
| smack_log(tracer_known->smk_known, |
| tracee_known->smk_known, |
| 0, rc, saip); |
| |
| rcu_read_unlock(); |
| return rc; |
| } |
| |
| /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */ |
| rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip); |
| |
| rcu_read_unlock(); |
| return rc; |
| } |
| |
| /* |
| * LSM hooks. |
| * We he, that is fun! |
| */ |
| |
| /** |
| * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH |
| * @ctp: child task pointer |
| * @mode: ptrace attachment mode (PTRACE_MODE_*) |
| * |
| * Returns 0 if access is OK, an error code otherwise |
| * |
| * Do the capability checks. |
| */ |
| static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode) |
| { |
| struct smack_known *skp; |
| |
| skp = smk_of_task_struct_obj(ctp); |
| |
| return smk_ptrace_rule_check(current, skp, mode, __func__); |
| } |
| |
| /** |
| * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME |
| * @ptp: parent task pointer |
| * |
| * Returns 0 if access is OK, an error code otherwise |
| * |
| * Do the capability checks, and require PTRACE_MODE_ATTACH. |
| */ |
| static int smack_ptrace_traceme(struct task_struct *ptp) |
| { |
| int rc; |
| struct smack_known *skp; |
| |
| skp = smk_of_task(smack_cred(current_cred())); |
| |
| rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__); |
| return rc; |
| } |
| |
| /** |
| * smack_syslog - Smack approval on syslog |
| * @typefrom_file: unused |
| * |
| * Returns 0 on success, error code otherwise. |
| */ |
| static int smack_syslog(int typefrom_file) |
| { |
| int rc = 0; |
| struct smack_known *skp = smk_of_current(); |
| |
| if (smack_privileged(CAP_MAC_OVERRIDE)) |
| return 0; |
| |
| if (smack_syslog_label != NULL && smack_syslog_label != skp) |
| rc = -EACCES; |
| |
| return rc; |
| } |
| |
| /* |
| * Superblock Hooks. |
| */ |
| |
| /** |
| * smack_sb_alloc_security - allocate a superblock blob |
| * @sb: the superblock getting the blob |
| * |
| * Returns 0 on success or -ENOMEM on error. |
| */ |
| static int smack_sb_alloc_security(struct super_block *sb) |
| { |
| struct superblock_smack *sbsp = smack_superblock(sb); |
| |
| sbsp->smk_root = &smack_known_floor; |
| sbsp->smk_default = &smack_known_floor; |
| sbsp->smk_floor = &smack_known_floor; |
| sbsp->smk_hat = &smack_known_hat; |
| /* |
| * SMK_SB_INITIALIZED will be zero from kzalloc. |
| */ |
| |
| return 0; |
| } |
| |
| struct smack_mnt_opts { |
| const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute; |
| }; |
| |
| static void smack_free_mnt_opts(void *mnt_opts) |
| { |
| struct smack_mnt_opts *opts = mnt_opts; |
| kfree(opts->fsdefault); |
| kfree(opts->fsfloor); |
| kfree(opts->fshat); |
| kfree(opts->fsroot); |
| kfree(opts->fstransmute); |
| kfree(opts); |
| } |
| |
| static int smack_add_opt(int token, const char *s, void **mnt_opts) |
| { |
| struct smack_mnt_opts *opts = *mnt_opts; |
| |
| if (!opts) { |
| opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); |
| if (!opts) |
| return -ENOMEM; |
| *mnt_opts = opts; |
| } |
| if (!s) |
| return -ENOMEM; |
| |
| switch (token) { |
| case Opt_fsdefault: |
| if (opts->fsdefault) |
| goto out_opt_err; |
| opts->fsdefault = s; |
| break; |
| case Opt_fsfloor: |
| if (opts->fsfloor) |
| goto out_opt_err; |
| opts->fsfloor = s; |
| break; |
| case Opt_fshat: |
| if (opts->fshat) |
| goto out_opt_err; |
| opts->fshat = s; |
| break; |
| case Opt_fsroot: |
| if (opts->fsroot) |
| goto out_opt_err; |
| opts->fsroot = s; |
| break; |
| case Opt_fstransmute: |
| if (opts->fstransmute) |
| goto out_opt_err; |
| opts->fstransmute = s; |
| break; |
| } |
| return 0; |
| |
| out_opt_err: |
| pr_warn("Smack: duplicate mount options\n"); |
| return -EINVAL; |
| } |
| |
| /** |
| * smack_fs_context_dup - Duplicate the security data on fs_context duplication |
| * @fc: The new filesystem context. |
| * @src_fc: The source filesystem context being duplicated. |
| * |
| * Returns 0 on success or -ENOMEM on error. |
| */ |
| static int smack_fs_context_dup(struct fs_context *fc, |
| struct fs_context *src_fc) |
| { |
| struct smack_mnt_opts *dst, *src = src_fc->security; |
| |
| if (!src) |
| return 0; |
| |
| fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); |
| if (!fc->security) |
| return -ENOMEM; |
| dst = fc->security; |
| |
| if (src->fsdefault) { |
| dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL); |
| if (!dst->fsdefault) |
| return -ENOMEM; |
| } |
| if (src->fsfloor) { |
| dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL); |
| if (!dst->fsfloor) |
| return -ENOMEM; |
| } |
| if (src->fshat) { |
| dst->fshat = kstrdup(src->fshat, GFP_KERNEL); |
| if (!dst->fshat) |
| return -ENOMEM; |
| } |
| if (src->fsroot) { |
| dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL); |
| if (!dst->fsroot) |
| return -ENOMEM; |
| } |
| if (src->fstransmute) { |
| dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL); |
| if (!dst->fstransmute) |
| return -ENOMEM; |
| } |
| return 0; |
| } |
| |
| static const struct fs_parameter_spec smack_fs_parameters[] = { |
| fsparam_string("smackfsdef", Opt_fsdefault), |
| fsparam_string("smackfsdefault", Opt_fsdefault), |
| fsparam_string("smackfsfloor", Opt_fsfloor), |
| fsparam_string("smackfshat", Opt_fshat), |
| fsparam_string("smackfsroot", Opt_fsroot), |
| fsparam_string("smackfstransmute", Opt_fstransmute), |
| {} |
| }; |
| |
| /** |
| * smack_fs_context_parse_param - Parse a single mount parameter |
| * @fc: The new filesystem context being constructed. |
| * @param: The parameter. |
| * |
| * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on |
| * error. |
| */ |
| static int smack_fs_context_parse_param(struct fs_context *fc, |
| struct fs_parameter *param) |
| { |
| struct fs_parse_result result; |
| int opt, rc; |
| |
| opt = fs_parse(fc, smack_fs_parameters, param, &result); |
| if (opt < 0) |
| return opt; |
| |
| rc = smack_add_opt(opt, param->string, &fc->security); |
| if (!rc) |
| param->string = NULL; |
| return rc; |
| } |
| |
| static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts) |
| { |
| char *from = options, *to = options; |
| bool first = true; |
| |
| while (1) { |
| char *next = strchr(from, ','); |
| int token, len, rc; |
| char *arg = NULL; |
| |
| if (next) |
| len = next - from; |
| else |
| len = strlen(from); |
| |
| token = match_opt_prefix(from, len, &arg); |
| if (token != Opt_error) { |
| arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL); |
| rc = smack_add_opt(token, arg, mnt_opts); |
| if (unlikely(rc)) { |
| kfree(arg); |
| if (*mnt_opts) |
| smack_free_mnt_opts(*mnt_opts); |
| *mnt_opts = NULL; |
| return rc; |
| } |
| } else { |
| if (!first) { // copy with preceding comma |
| from--; |
| len++; |
| } |
| if (to != from) |
| memmove(to, from, len); |
| to += len; |
| first = false; |
| } |
| if (!from[len]) |
| break; |
| from += len + 1; |
| } |
| *to = '\0'; |
| return 0; |
| } |
| |
| /** |
| * smack_set_mnt_opts - set Smack specific mount options |
| * @sb: the file system superblock |
| * @mnt_opts: Smack mount options |
| * @kern_flags: mount option from kernel space or user space |
| * @set_kern_flags: where to store converted mount opts |
| * |
| * Returns 0 on success, an error code on failure |
| * |
| * Allow filesystems with binary mount data to explicitly set Smack mount |
| * labels. |
| */ |
| static int smack_set_mnt_opts(struct super_block *sb, |
| void *mnt_opts, |
| unsigned long kern_flags, |
| unsigned long *set_kern_flags) |
| { |
| struct dentry *root = sb->s_root; |
| struct inode *inode = d_backing_inode(root); |
| struct superblock_smack *sp = smack_superblock(sb); |
| struct inode_smack *isp; |
| struct smack_known *skp; |
| struct smack_mnt_opts *opts = mnt_opts; |
| bool transmute = false; |
| |
| if (sp->smk_flags & SMK_SB_INITIALIZED) |
| return 0; |
| |
| if (!smack_privileged(CAP_MAC_ADMIN)) { |
| /* |
| * Unprivileged mounts don't get to specify Smack values. |
| */ |
| if (opts) |
| return -EPERM; |
| /* |
| * Unprivileged mounts get root and default from the caller. |
| */ |
| skp = smk_of_current(); |
| sp->smk_root = skp; |
| sp->smk_default = skp; |
| /* |
| * For a handful of fs types with no user-controlled |
| * backing store it's okay to trust security labels |
| * in the filesystem. The rest are untrusted. |
| */ |
| if (sb->s_user_ns != &init_user_ns && |
| sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC && |
| sb->s_magic != RAMFS_MAGIC) { |
| transmute = true; |
| sp->smk_flags |= SMK_SB_UNTRUSTED; |
| } |
| } |
| |
| sp->smk_flags |= SMK_SB_INITIALIZED; |
| |
| if (opts) { |
| if (opts->fsdefault) { |
| skp = smk_import_entry(opts->fsdefault, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_default = skp; |
| } |
| if (opts->fsfloor) { |
| skp = smk_import_entry(opts->fsfloor, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_floor = skp; |
| } |
| if (opts->fshat) { |
| skp = smk_import_entry(opts->fshat, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_hat = skp; |
| } |
| if (opts->fsroot) { |
| skp = smk_import_entry(opts->fsroot, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_root = skp; |
| } |
| if (opts->fstransmute) { |
| skp = smk_import_entry(opts->fstransmute, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| sp->smk_root = skp; |
| transmute = true; |
| } |
| } |
| |
| /* |
| * Initialize the root inode. |
| */ |
| init_inode_smack(inode, sp->smk_root); |
| |
| if (transmute) { |
| isp = smack_inode(inode); |
| isp->smk_flags |= SMK_INODE_TRANSMUTE; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smack_sb_statfs - Smack check on statfs |
| * @dentry: identifies the file system in question |
| * |
| * Returns 0 if current can read the floor of the filesystem, |
| * and error code otherwise |
| */ |
| static int smack_sb_statfs(struct dentry *dentry) |
| { |
| struct superblock_smack *sbp = smack_superblock(dentry->d_sb); |
| int rc; |
| struct smk_audit_info ad; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad); |
| rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc); |
| return rc; |
| } |
| |
| /* |
| * BPRM hooks |
| */ |
| |
| /** |
| * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec |
| * @bprm: the exec information |
| * |
| * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise |
| */ |
| static int smack_bprm_creds_for_exec(struct linux_binprm *bprm) |
| { |
| struct inode *inode = file_inode(bprm->file); |
| struct task_smack *bsp = smack_cred(bprm->cred); |
| struct inode_smack *isp; |
| struct superblock_smack *sbsp; |
| int rc; |
| |
| isp = smack_inode(inode); |
| if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task) |
| return 0; |
| |
| sbsp = smack_superblock(inode->i_sb); |
| if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) && |
| isp->smk_task != sbsp->smk_root) |
| return 0; |
| |
| if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
| struct task_struct *tracer; |
| rc = 0; |
| |
| rcu_read_lock(); |
| tracer = ptrace_parent(current); |
| if (likely(tracer != NULL)) |
| rc = smk_ptrace_rule_check(tracer, |
| isp->smk_task, |
| PTRACE_MODE_ATTACH, |
| __func__); |
| rcu_read_unlock(); |
| |
| if (rc != 0) |
| return rc; |
| } |
| if (bprm->unsafe & ~LSM_UNSAFE_PTRACE) |
| return -EPERM; |
| |
| bsp->smk_task = isp->smk_task; |
| bprm->per_clear |= PER_CLEAR_ON_SETID; |
| |
| /* Decide if this is a secure exec. */ |
| if (bsp->smk_task != bsp->smk_forked) |
| bprm->secureexec = 1; |
| |
| return 0; |
| } |
| |
| /* |
| * Inode hooks |
| */ |
| |
| /** |
| * smack_inode_alloc_security - allocate an inode blob |
| * @inode: the inode in need of a blob |
| * |
| * Returns 0 |
| */ |
| static int smack_inode_alloc_security(struct inode *inode) |
| { |
| struct smack_known *skp = smk_of_current(); |
| |
| init_inode_smack(inode, skp); |
| return 0; |
| } |
| |
| /** |
| * smack_inode_init_security - copy out the smack from an inode |
| * @inode: the newly created inode |
| * @dir: containing directory object |
| * @qstr: unused |
| * @name: where to put the attribute name |
| * @value: where to put the attribute value |
| * @len: where to put the length of the attribute |
| * |
| * Returns 0 if it all works out, -ENOMEM if there's no memory |
| */ |
| static int smack_inode_init_security(struct inode *inode, struct inode *dir, |
| const struct qstr *qstr, const char **name, |
| void **value, size_t *len) |
| { |
| struct inode_smack *issp = smack_inode(inode); |
| struct smack_known *skp = smk_of_current(); |
| struct smack_known *isp = smk_of_inode(inode); |
| struct smack_known *dsp = smk_of_inode(dir); |
| int may; |
| |
| if (name) |
| *name = XATTR_SMACK_SUFFIX; |
| |
| if (value && len) { |
| rcu_read_lock(); |
| may = smk_access_entry(skp->smk_known, dsp->smk_known, |
| &skp->smk_rules); |
| rcu_read_unlock(); |
| |
| /* |
| * If the access rule allows transmutation and |
| * the directory requests transmutation then |
| * by all means transmute. |
| * Mark the inode as changed. |
| */ |
| if (may > 0 && ((may & MAY_TRANSMUTE) != 0) && |
| smk_inode_transmutable(dir)) { |
| isp = dsp; |
| issp->smk_flags |= SMK_INODE_CHANGED; |
| } |
| |
| *value = kstrdup(isp->smk_known, GFP_NOFS); |
| if (*value == NULL) |
| return -ENOMEM; |
| |
| *len = strlen(isp->smk_known); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smack_inode_link - Smack check on link |
| * @old_dentry: the existing object |
| * @dir: unused |
| * @new_dentry: the new object |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, |
| struct dentry *new_dentry) |
| { |
| struct smack_known *isp; |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); |
| |
| isp = smk_of_inode(d_backing_inode(old_dentry)); |
| rc = smk_curacc(isp, MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc); |
| |
| if (rc == 0 && d_is_positive(new_dentry)) { |
| isp = smk_of_inode(d_backing_inode(new_dentry)); |
| smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); |
| rc = smk_curacc(isp, MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inode_unlink - Smack check on inode deletion |
| * @dir: containing directory object |
| * @dentry: file to unlink |
| * |
| * Returns 0 if current can write the containing directory |
| * and the object, error code otherwise |
| */ |
| static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) |
| { |
| struct inode *ip = d_backing_inode(dentry); |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| /* |
| * You need write access to the thing you're unlinking |
| */ |
| rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad); |
| rc = smk_bu_inode(ip, MAY_WRITE, rc); |
| if (rc == 0) { |
| /* |
| * You also need write access to the containing directory |
| */ |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); |
| smk_ad_setfield_u_fs_inode(&ad, dir); |
| rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dir, MAY_WRITE, rc); |
| } |
| return rc; |
| } |
| |
| /** |
| * smack_inode_rmdir - Smack check on directory deletion |
| * @dir: containing directory object |
| * @dentry: directory to unlink |
| * |
| * Returns 0 if current can write the containing directory |
| * and the directory, error code otherwise |
| */ |
| static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| /* |
| * You need write access to the thing you're removing |
| */ |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| if (rc == 0) { |
| /* |
| * You also need write access to the containing directory |
| */ |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); |
| smk_ad_setfield_u_fs_inode(&ad, dir); |
| rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad); |
| rc = smk_bu_inode(dir, MAY_WRITE, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inode_rename - Smack check on rename |
| * @old_inode: unused |
| * @old_dentry: the old object |
| * @new_inode: unused |
| * @new_dentry: the new object |
| * |
| * Read and write access is required on both the old and |
| * new directories. |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_rename(struct inode *old_inode, |
| struct dentry *old_dentry, |
| struct inode *new_inode, |
| struct dentry *new_dentry) |
| { |
| int rc; |
| struct smack_known *isp; |
| struct smk_audit_info ad; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry); |
| |
| isp = smk_of_inode(d_backing_inode(old_dentry)); |
| rc = smk_curacc(isp, MAY_READWRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc); |
| |
| if (rc == 0 && d_is_positive(new_dentry)) { |
| isp = smk_of_inode(d_backing_inode(new_dentry)); |
| smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry); |
| rc = smk_curacc(isp, MAY_READWRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc); |
| } |
| return rc; |
| } |
| |
| /** |
| * smack_inode_permission - Smack version of permission() |
| * @inode: the inode in question |
| * @mask: the access requested |
| * |
| * This is the important Smack hook. |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_permission(struct inode *inode, int mask) |
| { |
| struct superblock_smack *sbsp = smack_superblock(inode->i_sb); |
| struct smk_audit_info ad; |
| int no_block = mask & MAY_NOT_BLOCK; |
| int rc; |
| |
| mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
| /* |
| * No permission to check. Existence test. Yup, it's there. |
| */ |
| if (mask == 0) |
| return 0; |
| |
| if (sbsp->smk_flags & SMK_SB_UNTRUSTED) { |
| if (smk_of_inode(inode) != sbsp->smk_root) |
| return -EACCES; |
| } |
| |
| /* May be droppable after audit */ |
| if (no_block) |
| return -ECHILD; |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE); |
| smk_ad_setfield_u_fs_inode(&ad, inode); |
| rc = smk_curacc(smk_of_inode(inode), mask, &ad); |
| rc = smk_bu_inode(inode, mask, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_setattr - Smack check for setting attributes |
| * @dentry: the object |
| * @iattr: for the force flag |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| /* |
| * Need to allow for clearing the setuid bit. |
| */ |
| if (iattr->ia_valid & ATTR_FORCE) |
| return 0; |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_getattr - Smack check for getting attributes |
| * @path: path to extract the info from |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_getattr(const struct path *path) |
| { |
| struct smk_audit_info ad; |
| struct inode *inode = d_backing_inode(path->dentry); |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, *path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_inode(inode, MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_setxattr - Smack check for setting xattrs |
| * @mnt_userns: active user namespace |
| * @dentry: the object |
| * @name: name of the attribute |
| * @value: value of the attribute |
| * @size: size of the value |
| * @flags: unused |
| * |
| * This protects the Smack attribute explicitly. |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_setxattr(struct user_namespace *mnt_userns, |
| struct dentry *dentry, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp; |
| int check_priv = 0; |
| int check_import = 0; |
| int check_star = 0; |
| int rc = 0; |
| |
| /* |
| * Check label validity here so import won't fail in post_setxattr |
| */ |
| if (strcmp(name, XATTR_NAME_SMACK) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { |
| check_priv = 1; |
| check_import = 1; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || |
| strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| check_priv = 1; |
| check_import = 1; |
| check_star = 1; |
| } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { |
| check_priv = 1; |
| if (size != TRANS_TRUE_SIZE || |
| strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0) |
| rc = -EINVAL; |
| } else |
| rc = cap_inode_setxattr(dentry, name, value, size, flags); |
| |
| if (check_priv && !smack_privileged(CAP_MAC_ADMIN)) |
| rc = -EPERM; |
| |
| if (rc == 0 && check_import) { |
| skp = size ? smk_import_entry(value, size) : NULL; |
| if (IS_ERR(skp)) |
| rc = PTR_ERR(skp); |
| else if (skp == NULL || (check_star && |
| (skp == &smack_known_star || skp == &smack_known_web))) |
| rc = -EINVAL; |
| } |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| if (rc == 0) { |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inode_post_setxattr - Apply the Smack update approved above |
| * @dentry: object |
| * @name: attribute name |
| * @value: attribute value |
| * @size: attribute size |
| * @flags: unused |
| * |
| * Set the pointer in the inode blob to the entry found |
| * in the master label list. |
| */ |
| static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct smack_known *skp; |
| struct inode_smack *isp = smack_inode(d_backing_inode(dentry)); |
| |
| if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) { |
| isp->smk_flags |= SMK_INODE_TRANSMUTE; |
| return; |
| } |
| |
| if (strcmp(name, XATTR_NAME_SMACK) == 0) { |
| skp = smk_import_entry(value, size); |
| if (!IS_ERR(skp)) |
| isp->smk_inode = skp; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) { |
| skp = smk_import_entry(value, size); |
| if (!IS_ERR(skp)) |
| isp->smk_task = skp; |
| } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| skp = smk_import_entry(value, size); |
| if (!IS_ERR(skp)) |
| isp->smk_mmap = skp; |
| } |
| |
| return; |
| } |
| |
| /** |
| * smack_inode_getxattr - Smack check on getxattr |
| * @dentry: the object |
| * @name: unused |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_getxattr(struct dentry *dentry, const char *name) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_inode_removexattr - Smack check on removexattr |
| * @mnt_userns: active user namespace |
| * @dentry: the object |
| * @name: name of the attribute |
| * |
| * Removing the Smack attribute requires CAP_MAC_ADMIN |
| * |
| * Returns 0 if access is permitted, an error code otherwise |
| */ |
| static int smack_inode_removexattr(struct user_namespace *mnt_userns, |
| struct dentry *dentry, const char *name) |
| { |
| struct inode_smack *isp; |
| struct smk_audit_info ad; |
| int rc = 0; |
| |
| if (strcmp(name, XATTR_NAME_SMACK) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || |
| strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 || |
| strcmp(name, XATTR_NAME_SMACKEXEC) == 0 || |
| strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 || |
| strcmp(name, XATTR_NAME_SMACKMMAP) == 0) { |
| if (!smack_privileged(CAP_MAC_ADMIN)) |
| rc = -EPERM; |
| } else |
| rc = cap_inode_removexattr(mnt_userns, dentry, name); |
| |
| if (rc != 0) |
| return rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY); |
| smk_ad_setfield_u_fs_path_dentry(&ad, dentry); |
| |
| rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad); |
| rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc); |
| if (rc != 0) |
| return rc; |
| |
| isp = smack_inode(d_backing_inode(dentry)); |
| /* |
| * Don't do anything special for these. |
| * XATTR_NAME_SMACKIPIN |
| * XATTR_NAME_SMACKIPOUT |
| */ |
| if (strcmp(name, XATTR_NAME_SMACK) == 0) { |
| struct super_block *sbp = dentry->d_sb; |
| struct superblock_smack *sbsp = smack_superblock(sbp); |
| |
| isp->smk_inode = sbsp->smk_default; |
| } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) |
| isp->smk_task = NULL; |
| else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) |
| isp->smk_mmap = NULL; |
| else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) |
| isp->smk_flags &= ~SMK_INODE_TRANSMUTE; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_inode_getsecurity - get smack xattrs |
| * @mnt_userns: active user namespace |
| * @inode: the object |
| * @name: attribute name |
| * @buffer: where to put the result |
| * @alloc: duplicate memory |
| * |
| * Returns the size of the attribute or an error code |
| */ |
| static int smack_inode_getsecurity(struct user_namespace *mnt_userns, |
| struct inode *inode, const char *name, |
| void **buffer, bool alloc) |
| { |
| struct socket_smack *ssp; |
| struct socket *sock; |
| struct super_block *sbp; |
| struct inode *ip = (struct inode *)inode; |
| struct smack_known *isp; |
| |
| if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) |
| isp = smk_of_inode(inode); |
| else { |
| /* |
| * The rest of the Smack xattrs are only on sockets. |
| */ |
| sbp = ip->i_sb; |
| if (sbp->s_magic != SOCKFS_MAGIC) |
| return -EOPNOTSUPP; |
| |
| sock = SOCKET_I(ip); |
| if (sock == NULL || sock->sk == NULL) |
| return -EOPNOTSUPP; |
| |
| ssp = sock->sk->sk_security; |
| |
| if (strcmp(name, XATTR_SMACK_IPIN) == 0) |
| isp = ssp->smk_in; |
| else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) |
| isp = ssp->smk_out; |
| else |
| return -EOPNOTSUPP; |
| } |
| |
| if (alloc) { |
| *buffer = kstrdup(isp->smk_known, GFP_KERNEL); |
| if (*buffer == NULL) |
| return -ENOMEM; |
| } |
| |
| return strlen(isp->smk_known); |
| } |
| |
| |
| /** |
| * smack_inode_listsecurity - list the Smack attributes |
| * @inode: the object |
| * @buffer: where they go |
| * @buffer_size: size of buffer |
| */ |
| static int smack_inode_listsecurity(struct inode *inode, char *buffer, |
| size_t buffer_size) |
| { |
| int len = sizeof(XATTR_NAME_SMACK); |
| |
| if (buffer != NULL && len <= buffer_size) |
| memcpy(buffer, XATTR_NAME_SMACK, len); |
| |
| return len; |
| } |
| |
| /** |
| * smack_inode_getsecid - Extract inode's security id |
| * @inode: inode to extract the info from |
| * @secid: where result will be saved |
| */ |
| static void smack_inode_getsecid(struct inode *inode, u32 *secid) |
| { |
| struct smack_known *skp = smk_of_inode(inode); |
| |
| *secid = skp->smk_secid; |
| } |
| |
| /* |
| * File Hooks |
| */ |
| |
| /* |
| * There is no smack_file_permission hook |
| * |
| * Should access checks be done on each read or write? |
| * UNICOS and SELinux say yes. |
| * Trusted Solaris, Trusted Irix, and just about everyone else says no. |
| * |
| * I'll say no for now. Smack does not do the frequent |
| * label changing that SELinux does. |
| */ |
| |
| /** |
| * smack_file_alloc_security - assign a file security blob |
| * @file: the object |
| * |
| * The security blob for a file is a pointer to the master |
| * label list, so no allocation is done. |
| * |
| * f_security is the owner security information. It |
| * isn't used on file access checks, it's for send_sigio. |
| * |
| * Returns 0 |
| */ |
| static int smack_file_alloc_security(struct file *file) |
| { |
| struct smack_known **blob = smack_file(file); |
| |
| *blob = smk_of_current(); |
| return 0; |
| } |
| |
| /** |
| * smack_file_ioctl - Smack check on ioctls |
| * @file: the object |
| * @cmd: what to do |
| * @arg: unused |
| * |
| * Relies heavily on the correct use of the ioctl command conventions. |
| * |
| * Returns 0 if allowed, error code otherwise |
| */ |
| static int smack_file_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| int rc = 0; |
| struct smk_audit_info ad; |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| |
| if (_IOC_DIR(cmd) & _IOC_WRITE) { |
| rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); |
| rc = smk_bu_file(file, MAY_WRITE, rc); |
| } |
| |
| if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) { |
| rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_file(file, MAY_READ, rc); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_file_lock - Smack check on file locking |
| * @file: the object |
| * @cmd: unused |
| * |
| * Returns 0 if current has lock access, error code otherwise |
| */ |
| static int smack_file_lock(struct file *file, unsigned int cmd) |
| { |
| struct smk_audit_info ad; |
| int rc; |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); |
| rc = smk_bu_file(file, MAY_LOCK, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_file_fcntl - Smack check on fcntl |
| * @file: the object |
| * @cmd: what action to check |
| * @arg: unused |
| * |
| * Generally these operations are harmless. |
| * File locking operations present an obvious mechanism |
| * for passing information, so they require write access. |
| * |
| * Returns 0 if current has access, error code otherwise |
| */ |
| static int smack_file_fcntl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct smk_audit_info ad; |
| int rc = 0; |
| struct inode *inode = file_inode(file); |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| switch (cmd) { |
| case F_GETLK: |
| break; |
| case F_SETLK: |
| case F_SETLKW: |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad); |
| rc = smk_bu_file(file, MAY_LOCK, rc); |
| break; |
| case F_SETOWN: |
| case F_SETSIG: |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad); |
| rc = smk_bu_file(file, MAY_WRITE, rc); |
| break; |
| default: |
| break; |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_mmap_file - Check permissions for a mmap operation. |
| * @file: contains the file structure for file to map (may be NULL). |
| * @reqprot: contains the protection requested by the application. |
| * @prot: contains the protection that will be applied by the kernel. |
| * @flags: contains the operational flags. |
| * |
| * The @file may be NULL, e.g. if mapping anonymous memory. |
| * |
| * Return 0 if permission is granted. |
| */ |
| static int smack_mmap_file(struct file *file, |
| unsigned long reqprot, unsigned long prot, |
| unsigned long flags) |
| { |
| struct smack_known *skp; |
| struct smack_known *mkp; |
| struct smack_rule *srp; |
| struct task_smack *tsp; |
| struct smack_known *okp; |
| struct inode_smack *isp; |
| struct superblock_smack *sbsp; |
| int may; |
| int mmay; |
| int tmay; |
| int rc; |
| |
| if (file == NULL) |
| return 0; |
| |
| if (unlikely(IS_PRIVATE(file_inode(file)))) |
| return 0; |
| |
| isp = smack_inode(file_inode(file)); |
| if (isp->smk_mmap == NULL) |
| return 0; |
| sbsp = smack_superblock(file_inode(file)->i_sb); |
| if (sbsp->smk_flags & SMK_SB_UNTRUSTED && |
| isp->smk_mmap != sbsp->smk_root) |
| return -EACCES; |
| mkp = isp->smk_mmap; |
| |
| tsp = smack_cred(current_cred()); |
| skp = smk_of_current(); |
| rc = 0; |
| |
| rcu_read_lock(); |
| /* |
| * For each Smack rule associated with the subject |
| * label verify that the SMACK64MMAP also has access |
| * to that rule's object label. |
| */ |
| list_for_each_entry_rcu(srp, &skp->smk_rules, list) { |
| okp = srp->smk_object; |
| /* |
| * Matching labels always allows access. |
| */ |
| if (mkp->smk_known == okp->smk_known) |
| continue; |
| /* |
| * If there is a matching local rule take |
| * that into account as well. |
| */ |
| may = smk_access_entry(srp->smk_subject->smk_known, |
| okp->smk_known, |
| &tsp->smk_rules); |
| if (may == -ENOENT) |
| may = srp->smk_access; |
| else |
| may &= srp->smk_access; |
| /* |
| * If may is zero the SMACK64MMAP subject can't |
| * possibly have less access. |
| */ |
| if (may == 0) |
| continue; |
| |
| /* |
| * Fetch the global list entry. |
| * If there isn't one a SMACK64MMAP subject |
| * can't have as much access as current. |
| */ |
| mmay = smk_access_entry(mkp->smk_known, okp->smk_known, |
| &mkp->smk_rules); |
| if (mmay == -ENOENT) { |
| rc = -EACCES; |
| break; |
| } |
| /* |
| * If there is a local entry it modifies the |
| * potential access, too. |
| */ |
| tmay = smk_access_entry(mkp->smk_known, okp->smk_known, |
| &tsp->smk_rules); |
| if (tmay != -ENOENT) |
| mmay &= tmay; |
| |
| /* |
| * If there is any access available to current that is |
| * not available to a SMACK64MMAP subject |
| * deny access. |
| */ |
| if ((may | mmay) != mmay) { |
| rc = -EACCES; |
| break; |
| } |
| } |
| |
| rcu_read_unlock(); |
| |
| return rc; |
| } |
| |
| /** |
| * smack_file_set_fowner - set the file security blob value |
| * @file: object in question |
| * |
| */ |
| static void smack_file_set_fowner(struct file *file) |
| { |
| struct smack_known **blob = smack_file(file); |
| |
| *blob = smk_of_current(); |
| } |
| |
| /** |
| * smack_file_send_sigiotask - Smack on sigio |
| * @tsk: The target task |
| * @fown: the object the signal come from |
| * @signum: unused |
| * |
| * Allow a privileged task to get signals even if it shouldn't |
| * |
| * Returns 0 if a subject with the object's smack could |
| * write to the task, an error code otherwise. |
| */ |
| static int smack_file_send_sigiotask(struct task_struct *tsk, |
| struct fown_struct *fown, int signum) |
| { |
| struct smack_known **blob; |
| struct smack_known *skp; |
| struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred)); |
| const struct cred *tcred; |
| struct file *file; |
| int rc; |
| struct smk_audit_info ad; |
| |
| /* |
| * struct fown_struct is never outside the context of a struct file |
| */ |
| file = container_of(fown, struct file, f_owner); |
| |
| /* we don't log here as rc can be overriden */ |
| blob = smack_file(file); |
| skp = *blob; |
| rc = smk_access(skp, tkp, MAY_DELIVER, NULL); |
| rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc); |
| |
| rcu_read_lock(); |
| tcred = __task_cred(tsk); |
| if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred)) |
| rc = 0; |
| rcu_read_unlock(); |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, tsk); |
| smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad); |
| return rc; |
| } |
| |
| /** |
| * smack_file_receive - Smack file receive check |
| * @file: the object |
| * |
| * Returns 0 if current has access, error code otherwise |
| */ |
| static int smack_file_receive(struct file *file) |
| { |
| int rc; |
| int may = 0; |
| struct smk_audit_info ad; |
| struct inode *inode = file_inode(file); |
| struct socket *sock; |
| struct task_smack *tsp; |
| struct socket_smack *ssp; |
| |
| if (unlikely(IS_PRIVATE(inode))) |
| return 0; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| |
| if (inode->i_sb->s_magic == SOCKFS_MAGIC) { |
| sock = SOCKET_I(inode); |
| ssp = sock->sk->sk_security; |
| tsp = smack_cred(current_cred()); |
| /* |
| * If the receiving process can't write to the |
| * passed socket or if the passed socket can't |
| * write to the receiving process don't accept |
| * the passed socket. |
| */ |
| rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad); |
| rc = smk_bu_file(file, may, rc); |
| if (rc < 0) |
| return rc; |
| rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad); |
| rc = smk_bu_file(file, may, rc); |
| return rc; |
| } |
| /* |
| * This code relies on bitmasks. |
| */ |
| if (file->f_mode & FMODE_READ) |
| may = MAY_READ; |
| if (file->f_mode & FMODE_WRITE) |
| may |= MAY_WRITE; |
| |
| rc = smk_curacc(smk_of_inode(inode), may, &ad); |
| rc = smk_bu_file(file, may, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_file_open - Smack dentry open processing |
| * @file: the object |
| * |
| * Set the security blob in the file structure. |
| * Allow the open only if the task has read access. There are |
| * many read operations (e.g. fstat) that you can do with an |
| * fd even if you have the file open write-only. |
| * |
| * Returns 0 if current has access, error code otherwise |
| */ |
| static int smack_file_open(struct file *file) |
| { |
| struct task_smack *tsp = smack_cred(file->f_cred); |
| struct inode *inode = file_inode(file); |
| struct smk_audit_info ad; |
| int rc; |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); |
| |
| return rc; |
| } |
| |
| /* |
| * Task hooks |
| */ |
| |
| /** |
| * smack_cred_alloc_blank - "allocate" blank task-level security credentials |
| * @cred: the new credentials |
| * @gfp: the atomicity of any memory allocations |
| * |
| * Prepare a blank set of credentials for modification. This must allocate all |
| * the memory the LSM module might require such that cred_transfer() can |
| * complete without error. |
| */ |
| static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) |
| { |
| init_task_smack(smack_cred(cred), NULL, NULL); |
| return 0; |
| } |
| |
| |
| /** |
| * smack_cred_free - "free" task-level security credentials |
| * @cred: the credentials in question |
| * |
| */ |
| static void smack_cred_free(struct cred *cred) |
| { |
| struct task_smack *tsp = smack_cred(cred); |
| struct smack_rule *rp; |
| struct list_head *l; |
| struct list_head *n; |
| |
| smk_destroy_label_list(&tsp->smk_relabel); |
| |
| list_for_each_safe(l, n, &tsp->smk_rules) { |
| rp = list_entry(l, struct smack_rule, list); |
| list_del(&rp->list); |
| kmem_cache_free(smack_rule_cache, rp); |
| } |
| } |
| |
| /** |
| * smack_cred_prepare - prepare new set of credentials for modification |
| * @new: the new credentials |
| * @old: the original credentials |
| * @gfp: the atomicity of any memory allocations |
| * |
| * Prepare a new set of credentials for modification. |
| */ |
| static int smack_cred_prepare(struct cred *new, const struct cred *old, |
| gfp_t gfp) |
| { |
| struct task_smack *old_tsp = smack_cred(old); |
| struct task_smack *new_tsp = smack_cred(new); |
| int rc; |
| |
| init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); |
| |
| rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); |
| if (rc != 0) |
| return rc; |
| |
| rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, |
| gfp); |
| return rc; |
| } |
| |
| /** |
| * smack_cred_transfer - Transfer the old credentials to the new credentials |
| * @new: the new credentials |
| * @old: the original credentials |
| * |
| * Fill in a set of blank credentials from another set of credentials. |
| */ |
| static void smack_cred_transfer(struct cred *new, const struct cred *old) |
| { |
| struct task_smack *old_tsp = smack_cred(old); |
| struct task_smack *new_tsp = smack_cred(new); |
| |
| new_tsp->smk_task = old_tsp->smk_task; |
| new_tsp->smk_forked = old_tsp->smk_task; |
| mutex_init(&new_tsp->smk_rules_lock); |
| INIT_LIST_HEAD(&new_tsp->smk_rules); |
| |
| /* cbs copy rule list */ |
| } |
| |
| /** |
| * smack_cred_getsecid - get the secid corresponding to a creds structure |
| * @cred: the object creds |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the smack label. |
| */ |
| static void smack_cred_getsecid(const struct cred *cred, u32 *secid) |
| { |
| struct smack_known *skp; |
| |
| rcu_read_lock(); |
| skp = smk_of_task(smack_cred(cred)); |
| *secid = skp->smk_secid; |
| rcu_read_unlock(); |
| } |
| |
| /** |
| * smack_kernel_act_as - Set the subjective context in a set of credentials |
| * @new: points to the set of credentials to be modified. |
| * @secid: specifies the security ID to be set |
| * |
| * Set the security data for a kernel service. |
| */ |
| static int smack_kernel_act_as(struct cred *new, u32 secid) |
| { |
| struct task_smack *new_tsp = smack_cred(new); |
| |
| new_tsp->smk_task = smack_from_secid(secid); |
| return 0; |
| } |
| |
| /** |
| * smack_kernel_create_files_as - Set the file creation label in a set of creds |
| * @new: points to the set of credentials to be modified |
| * @inode: points to the inode to use as a reference |
| * |
| * Set the file creation context in a set of credentials to the same |
| * as the objective context of the specified inode |
| */ |
| static int smack_kernel_create_files_as(struct cred *new, |
| struct inode *inode) |
| { |
| struct inode_smack *isp = smack_inode(inode); |
| struct task_smack *tsp = smack_cred(new); |
| |
| tsp->smk_forked = isp->smk_inode; |
| tsp->smk_task = tsp->smk_forked; |
| return 0; |
| } |
| |
| /** |
| * smk_curacc_on_task - helper to log task related access |
| * @p: the task object |
| * @access: the access requested |
| * @caller: name of the calling function for audit |
| * |
| * Return 0 if access is permitted |
| */ |
| static int smk_curacc_on_task(struct task_struct *p, int access, |
| const char *caller) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| int rc; |
| |
| smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, p); |
| rc = smk_curacc(skp, access, &ad); |
| rc = smk_bu_task(p, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_task_setpgid - Smack check on setting pgid |
| * @p: the task object |
| * @pgid: unused |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_setpgid(struct task_struct *p, pid_t pgid) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_getpgid - Smack access check for getpgid |
| * @p: the object task |
| * |
| * Returns 0 if current can read the object task, error code otherwise |
| */ |
| static int smack_task_getpgid(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_task_getsid - Smack access check for getsid |
| * @p: the object task |
| * |
| * Returns 0 if current can read the object task, error code otherwise |
| */ |
| static int smack_task_getsid(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_current_getsecid_subj - get the subjective secid of the current task |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the task's subjective smack label. |
| */ |
| static void smack_current_getsecid_subj(u32 *secid) |
| { |
| struct smack_known *skp = smk_of_current(); |
| |
| *secid = skp->smk_secid; |
| } |
| |
| /** |
| * smack_task_getsecid_obj - get the objective secid of the task |
| * @p: the task |
| * @secid: where to put the result |
| * |
| * Sets the secid to contain a u32 version of the task's objective smack label. |
| */ |
| static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid) |
| { |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| |
| *secid = skp->smk_secid; |
| } |
| |
| /** |
| * smack_task_setnice - Smack check on setting nice |
| * @p: the task object |
| * @nice: unused |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_setnice(struct task_struct *p, int nice) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_setioprio - Smack check on setting ioprio |
| * @p: the task object |
| * @ioprio: unused |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_setioprio(struct task_struct *p, int ioprio) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_getioprio - Smack check on reading ioprio |
| * @p: the task object |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_getioprio(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_task_setscheduler - Smack check on setting scheduler |
| * @p: the task object |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_setscheduler(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_getscheduler - Smack check on reading scheduler |
| * @p: the task object |
| * |
| * Return 0 if read access is permitted |
| */ |
| static int smack_task_getscheduler(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_READ, __func__); |
| } |
| |
| /** |
| * smack_task_movememory - Smack check on moving memory |
| * @p: the task object |
| * |
| * Return 0 if write access is permitted |
| */ |
| static int smack_task_movememory(struct task_struct *p) |
| { |
| return smk_curacc_on_task(p, MAY_WRITE, __func__); |
| } |
| |
| /** |
| * smack_task_kill - Smack check on signal delivery |
| * @p: the task object |
| * @info: unused |
| * @sig: unused |
| * @cred: identifies the cred to use in lieu of current's |
| * |
| * Return 0 if write access is permitted |
| * |
| */ |
| static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info, |
| int sig, const struct cred *cred) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *skp; |
| struct smack_known *tkp = smk_of_task_struct_obj(p); |
| int rc; |
| |
| if (!sig) |
| return 0; /* null signal; existence test */ |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); |
| smk_ad_setfield_u_tsk(&ad, p); |
| /* |
| * Sending a signal requires that the sender |
| * can write the receiver. |
| */ |
| if (cred == NULL) { |
| rc = smk_curacc(tkp, MAY_DELIVER, &ad); |
| rc = smk_bu_task(p, MAY_DELIVER, rc); |
| return rc; |
| } |
| /* |
| * If the cred isn't NULL we're dealing with some USB IO |
| * specific behavior. This is not clean. For one thing |
| * we can't take privilege into account. |
| */ |
| skp = smk_of_task(smack_cred(cred)); |
| rc = smk_access(skp, tkp, MAY_DELIVER, &ad); |
| rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_task_to_inode - copy task smack into the inode blob |
| * @p: task to copy from |
| * @inode: inode to copy to |
| * |
| * Sets the smack pointer in the inode security blob |
| */ |
| static void smack_task_to_inode(struct task_struct *p, struct inode *inode) |
| { |
| struct inode_smack *isp = smack_inode(inode); |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| |
| isp->smk_inode = skp; |
| isp->smk_flags |= SMK_INODE_INSTANT; |
| } |
| |
| /* |
| * Socket hooks. |
| */ |
| |
| /** |
| * smack_sk_alloc_security - Allocate a socket blob |
| * @sk: the socket |
| * @family: unused |
| * @gfp_flags: memory allocation flags |
| * |
| * Assign Smack pointers to current |
| * |
| * Returns 0 on success, -ENOMEM is there's no memory |
| */ |
| static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) |
| { |
| struct smack_known *skp = smk_of_current(); |
| struct socket_smack *ssp; |
| |
| ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); |
| if (ssp == NULL) |
| return -ENOMEM; |
| |
| /* |
| * Sockets created by kernel threads receive web label. |
| */ |
| if (unlikely(current->flags & PF_KTHREAD)) { |
| ssp->smk_in = &smack_known_web; |
| ssp->smk_out = &smack_known_web; |
| } else { |
| ssp->smk_in = skp; |
| ssp->smk_out = skp; |
| } |
| ssp->smk_packet = NULL; |
| |
| sk->sk_security = ssp; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_sk_free_security - Free a socket blob |
| * @sk: the socket |
| * |
| * Clears the blob pointer |
| */ |
| static void smack_sk_free_security(struct sock *sk) |
| { |
| #ifdef SMACK_IPV6_PORT_LABELING |
| struct smk_port_label *spp; |
| |
| if (sk->sk_family == PF_INET6) { |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_sock != sk) |
| continue; |
| spp->smk_can_reuse = 1; |
| break; |
| } |
| rcu_read_unlock(); |
| } |
| #endif |
| kfree(sk->sk_security); |
| } |
| |
| /** |
| * smack_ipv4host_label - check host based restrictions |
| * @sip: the object end |
| * |
| * looks for host based access restrictions |
| * |
| * This version will only be appropriate for really small sets of single label |
| * hosts. The caller is responsible for ensuring that the RCU read lock is |
| * taken before calling this function. |
| * |
| * Returns the label of the far end or NULL if it's not special. |
| */ |
| static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip) |
| { |
| struct smk_net4addr *snp; |
| struct in_addr *siap = &sip->sin_addr; |
| |
| if (siap->s_addr == 0) |
| return NULL; |
| |
| list_for_each_entry_rcu(snp, &smk_net4addr_list, list) |
| /* |
| * we break after finding the first match because |
| * the list is sorted from longest to shortest mask |
| * so we have found the most specific match |
| */ |
| if (snp->smk_host.s_addr == |
| (siap->s_addr & snp->smk_mask.s_addr)) |
| return snp->smk_label; |
| |
| return NULL; |
| } |
| |
| /* |
| * smk_ipv6_localhost - Check for local ipv6 host address |
| * @sip: the address |
| * |
| * Returns boolean true if this is the localhost address |
| */ |
| static bool smk_ipv6_localhost(struct sockaddr_in6 *sip) |
| { |
| __be16 *be16p = (__be16 *)&sip->sin6_addr; |
| __be32 *be32p = (__be32 *)&sip->sin6_addr; |
| |
| if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 && |
| ntohs(be16p[7]) == 1) |
| return true; |
| return false; |
| } |
| |
| /** |
| * smack_ipv6host_label - check host based restrictions |
| * @sip: the object end |
| * |
| * looks for host based access restrictions |
| * |
| * This version will only be appropriate for really small sets of single label |
| * hosts. The caller is responsible for ensuring that the RCU read lock is |
| * taken before calling this function. |
| * |
| * Returns the label of the far end or NULL if it's not special. |
| */ |
| static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip) |
| { |
| struct smk_net6addr *snp; |
| struct in6_addr *sap = &sip->sin6_addr; |
| int i; |
| int found = 0; |
| |
| /* |
| * It's local. Don't look for a host label. |
| */ |
| if (smk_ipv6_localhost(sip)) |
| return NULL; |
| |
| list_for_each_entry_rcu(snp, &smk_net6addr_list, list) { |
| /* |
| * If the label is NULL the entry has |
| * been renounced. Ignore it. |
| */ |
| if (snp->smk_label == NULL) |
| continue; |
| /* |
| * we break after finding the first match because |
| * the list is sorted from longest to shortest mask |
| * so we have found the most specific match |
| */ |
| for (found = 1, i = 0; i < 8; i++) { |
| if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) != |
| snp->smk_host.s6_addr16[i]) { |
| found = 0; |
| break; |
| } |
| } |
| if (found) |
| return snp->smk_label; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * smack_netlbl_add - Set the secattr on a socket |
| * @sk: the socket |
| * |
| * Attach the outbound smack value (smk_out) to the socket. |
| * |
| * Returns 0 on success or an error code |
| */ |
| static int smack_netlbl_add(struct sock *sk) |
| { |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp = ssp->smk_out; |
| int rc; |
| |
| local_bh_disable(); |
| bh_lock_sock_nested(sk); |
| |
| rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel); |
| switch (rc) { |
| case 0: |
| ssp->smk_state = SMK_NETLBL_LABELED; |
| break; |
| case -EDESTADDRREQ: |
| ssp->smk_state = SMK_NETLBL_REQSKB; |
| rc = 0; |
| break; |
| } |
| |
| bh_unlock_sock(sk); |
| local_bh_enable(); |
| |
| return rc; |
| } |
| |
| /** |
| * smack_netlbl_delete - Remove the secattr from a socket |
| * @sk: the socket |
| * |
| * Remove the outbound smack value from a socket |
| */ |
| static void smack_netlbl_delete(struct sock *sk) |
| { |
| struct socket_smack *ssp = sk->sk_security; |
| |
| /* |
| * Take the label off the socket if one is set. |
| */ |
| if (ssp->smk_state != SMK_NETLBL_LABELED) |
| return; |
| |
| local_bh_disable(); |
| bh_lock_sock_nested(sk); |
| netlbl_sock_delattr(sk); |
| bh_unlock_sock(sk); |
| local_bh_enable(); |
| ssp->smk_state = SMK_NETLBL_UNLABELED; |
| } |
| |
| /** |
| * smk_ipv4_check - Perform IPv4 host access checks |
| * @sk: the socket |
| * @sap: the destination address |
| * |
| * Set the correct secattr for the given socket based on the destination |
| * address and perform any outbound access checks needed. |
| * |
| * Returns 0 on success or an error code. |
| * |
| */ |
| static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap) |
| { |
| struct smack_known *skp; |
| int rc = 0; |
| struct smack_known *hkp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct smk_audit_info ad; |
| |
| rcu_read_lock(); |
| hkp = smack_ipv4host_label(sap); |
| if (hkp != NULL) { |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = sap->sin_family; |
| ad.a.u.net->dport = sap->sin_port; |
| ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr; |
| #endif |
| skp = ssp->smk_out; |
| rc = smk_access(skp, hkp, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc); |
| /* |
| * Clear the socket netlabel if it's set. |
| */ |
| if (!rc) |
| smack_netlbl_delete(sk); |
| } |
| rcu_read_unlock(); |
| |
| return rc; |
| } |
| |
| /** |
| * smk_ipv6_check - check Smack access |
| * @subject: subject Smack label |
| * @object: object Smack label |
| * @address: address |
| * @act: the action being taken |
| * |
| * Check an IPv6 access |
| */ |
| static int smk_ipv6_check(struct smack_known *subject, |
| struct smack_known *object, |
| struct sockaddr_in6 *address, int act) |
| { |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = PF_INET6; |
| ad.a.u.net->dport = address->sin6_port; |
| if (act == SMK_RECEIVING) |
| ad.a.u.net->v6info.saddr = address->sin6_addr; |
| else |
| ad.a.u.net->v6info.daddr = address->sin6_addr; |
| #endif |
| rc = smk_access(subject, object, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc); |
| return rc; |
| } |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| /** |
| * smk_ipv6_port_label - Smack port access table management |
| * @sock: socket |
| * @address: address |
| * |
| * Create or update the port list entry |
| */ |
| static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address) |
| { |
| struct sock *sk = sock->sk; |
| struct sockaddr_in6 *addr6; |
| struct socket_smack *ssp = sock->sk->sk_security; |
| struct smk_port_label *spp; |
| unsigned short port = 0; |
| |
| if (address == NULL) { |
| /* |
| * This operation is changing the Smack information |
| * on the bound socket. Take the changes to the port |
| * as well. |
| */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (sk != spp->smk_sock) |
| continue; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| rcu_read_unlock(); |
| return; |
| } |
| /* |
| * A NULL address is only used for updating existing |
| * bound entries. If there isn't one, it's OK. |
| */ |
| rcu_read_unlock(); |
| return; |
| } |
| |
| addr6 = (struct sockaddr_in6 *)address; |
| port = ntohs(addr6->sin6_port); |
| /* |
| * This is a special case that is safely ignored. |
| */ |
| if (port == 0) |
| return; |
| |
| /* |
| * Look for an existing port list entry. |
| * This is an indication that a port is getting reused. |
| */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_port != port || spp->smk_sock_type != sock->type) |
| continue; |
| if (spp->smk_can_reuse != 1) { |
| rcu_read_unlock(); |
| return; |
| } |
| spp->smk_port = port; |
| spp->smk_sock = sk; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| spp->smk_can_reuse = 0; |
| rcu_read_unlock(); |
| return; |
| } |
| rcu_read_unlock(); |
| /* |
| * A new port entry is required. |
| */ |
| spp = kzalloc(sizeof(*spp), GFP_KERNEL); |
| if (spp == NULL) |
| return; |
| |
| spp->smk_port = port; |
| spp->smk_sock = sk; |
| spp->smk_in = ssp->smk_in; |
| spp->smk_out = ssp->smk_out; |
| spp->smk_sock_type = sock->type; |
| spp->smk_can_reuse = 0; |
| |
| mutex_lock(&smack_ipv6_lock); |
| list_add_rcu(&spp->list, &smk_ipv6_port_list); |
| mutex_unlock(&smack_ipv6_lock); |
| return; |
| } |
| |
| /** |
| * smk_ipv6_port_check - check Smack port access |
| * @sk: socket |
| * @address: address |
| * @act: the action being taken |
| * |
| * Create or update the port list entry |
| */ |
| static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address, |
| int act) |
| { |
| struct smk_port_label *spp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp = NULL; |
| unsigned short port; |
| struct smack_known *object; |
| |
| if (act == SMK_RECEIVING) { |
| skp = smack_ipv6host_label(address); |
| object = ssp->smk_in; |
| } else { |
| skp = ssp->smk_out; |
| object = smack_ipv6host_label(address); |
| } |
| |
| /* |
| * The other end is a single label host. |
| */ |
| if (skp != NULL && object != NULL) |
| return smk_ipv6_check(skp, object, address, act); |
| if (skp == NULL) |
| skp = smack_net_ambient; |
| if (object == NULL) |
| object = smack_net_ambient; |
| |
| /* |
| * It's remote, so port lookup does no good. |
| */ |
| if (!smk_ipv6_localhost(address)) |
| return smk_ipv6_check(skp, object, address, act); |
| |
| /* |
| * It's local so the send check has to have passed. |
| */ |
| if (act == SMK_RECEIVING) |
| return 0; |
| |
| port = ntohs(address->sin6_port); |
| rcu_read_lock(); |
| list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) { |
| if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type) |
| continue; |
| object = spp->smk_in; |
| if (act == SMK_CONNECTING) |
| ssp->smk_packet = spp->smk_out; |
| break; |
| } |
| rcu_read_unlock(); |
| |
| return smk_ipv6_check(skp, object, address, act); |
| } |
| #endif |
| |
| /** |
| * smack_inode_setsecurity - set smack xattrs |
| * @inode: the object |
| * @name: attribute name |
| * @value: attribute value |
| * @size: size of the attribute |
| * @flags: unused |
| * |
| * Sets the named attribute in the appropriate blob |
| * |
| * Returns 0 on success, or an error code |
| */ |
| static int smack_inode_setsecurity(struct inode *inode, const char *name, |
| const void *value, size_t size, int flags) |
| { |
| struct smack_known *skp; |
| struct inode_smack *nsp = smack_inode(inode); |
| struct socket_smack *ssp; |
| struct socket *sock; |
| int rc = 0; |
| |
| if (value == NULL || size > SMK_LONGLABEL || size == 0) |
| return -EINVAL; |
| |
| skp = smk_import_entry(value, size); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| |
| if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { |
| nsp->smk_inode = skp; |
| nsp->smk_flags |= SMK_INODE_INSTANT; |
| return 0; |
| } |
| /* |
| * The rest of the Smack xattrs are only on sockets. |
| */ |
| if (inode->i_sb->s_magic != SOCKFS_MAGIC) |
| return -EOPNOTSUPP; |
| |
| sock = SOCKET_I(inode); |
| if (sock == NULL || sock->sk == NULL) |
| return -EOPNOTSUPP; |
| |
| ssp = sock->sk->sk_security; |
| |
| if (strcmp(name, XATTR_SMACK_IPIN) == 0) |
| ssp->smk_in = skp; |
| else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { |
| ssp->smk_out = skp; |
| if (sock->sk->sk_family == PF_INET) { |
| rc = smack_netlbl_add(sock->sk); |
| if (rc != 0) |
| printk(KERN_WARNING |
| "Smack: \"%s\" netlbl error %d.\n", |
| __func__, -rc); |
| } |
| } else |
| return -EOPNOTSUPP; |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| if (sock->sk->sk_family == PF_INET6) |
| smk_ipv6_port_label(sock, NULL); |
| #endif |
| |
| return 0; |
| } |
| |
| /** |
| * smack_socket_post_create - finish socket setup |
| * @sock: the socket |
| * @family: protocol family |
| * @type: unused |
| * @protocol: unused |
| * @kern: unused |
| * |
| * Sets the netlabel information on the socket |
| * |
| * Returns 0 on success, and error code otherwise |
| */ |
| static int smack_socket_post_create(struct socket *sock, int family, |
| int type, int protocol, int kern) |
| { |
| struct socket_smack *ssp; |
| |
| if (sock->sk == NULL) |
| return 0; |
| |
| /* |
| * Sockets created by kernel threads receive web label. |
| */ |
| if (unlikely(current->flags & PF_KTHREAD)) { |
| ssp = sock->sk->sk_security; |
| ssp->smk_in = &smack_known_web; |
| ssp->smk_out = &smack_known_web; |
| } |
| |
| if (family != PF_INET) |
| return 0; |
| /* |
| * Set the outbound netlbl. |
| */ |
| return smack_netlbl_add(sock->sk); |
| } |
| |
| /** |
| * smack_socket_socketpair - create socket pair |
| * @socka: one socket |
| * @sockb: another socket |
| * |
| * Cross reference the peer labels for SO_PEERSEC |
| * |
| * Returns 0 |
| */ |
| static int smack_socket_socketpair(struct socket *socka, |
| struct socket *sockb) |
| { |
| struct socket_smack *asp = socka->sk->sk_security; |
| struct socket_smack *bsp = sockb->sk->sk_security; |
| |
| asp->smk_packet = bsp->smk_out; |
| bsp->smk_packet = asp->smk_out; |
| |
| return 0; |
| } |
| |
| #ifdef SMACK_IPV6_PORT_LABELING |
| /** |
| * smack_socket_bind - record port binding information. |
| * @sock: the socket |
| * @address: the port address |
| * @addrlen: size of the address |
| * |
| * Records the label bound to a port. |
| * |
| * Returns 0 on success, and error code otherwise |
| */ |
| static int smack_socket_bind(struct socket *sock, struct sockaddr *address, |
| int addrlen) |
| { |
| if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) { |
| if (addrlen < SIN6_LEN_RFC2133 || |
| address->sa_family != AF_INET6) |
| return -EINVAL; |
| smk_ipv6_port_label(sock, address); |
| } |
| return 0; |
| } |
| #endif /* SMACK_IPV6_PORT_LABELING */ |
| |
| /** |
| * smack_socket_connect - connect access check |
| * @sock: the socket |
| * @sap: the other end |
| * @addrlen: size of sap |
| * |
| * Verifies that a connection may be possible |
| * |
| * Returns 0 on success, and error code otherwise |
| */ |
| static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, |
| int addrlen) |
| { |
| int rc = 0; |
| |
| if (sock->sk == NULL) |
| return 0; |
| if (sock->sk->sk_family != PF_INET && |
| (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6)) |
| return 0; |
| if (addrlen < offsetofend(struct sockaddr, sa_family)) |
| return 0; |
| if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) { |
| struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap; |
| struct smack_known *rsp = NULL; |
| |
| if (addrlen < SIN6_LEN_RFC2133) |
| return 0; |
| if (__is_defined(SMACK_IPV6_SECMARK_LABELING)) |
| rsp = smack_ipv6host_label(sip); |
| if (rsp != NULL) { |
| struct socket_smack *ssp = sock->sk->sk_security; |
| |
| rc = smk_ipv6_check(ssp->smk_out, rsp, sip, |
| SMK_CONNECTING); |
| } |
| #ifdef SMACK_IPV6_PORT_LABELING |
| rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING); |
| #endif |
| |
| return rc; |
| } |
| if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in)) |
| return 0; |
| rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap); |
| return rc; |
| } |
| |
| /** |
| * smack_flags_to_may - convert S_ to MAY_ values |
| * @flags: the S_ value |
| * |
| * Returns the equivalent MAY_ value |
| */ |
| static int smack_flags_to_may(int flags) |
| { |
| int may = 0; |
| |
| if (flags & S_IRUGO) |
| may |= MAY_READ; |
| if (flags & S_IWUGO) |
| may |= MAY_WRITE; |
| if (flags & S_IXUGO) |
| may |= MAY_EXEC; |
| |
| return may; |
| } |
| |
| /** |
| * smack_msg_msg_alloc_security - Set the security blob for msg_msg |
| * @msg: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_msg_msg_alloc_security(struct msg_msg *msg) |
| { |
| struct smack_known **blob = smack_msg_msg(msg); |
| |
| *blob = smk_of_current(); |
| return 0; |
| } |
| |
| /** |
| * smack_of_ipc - the smack pointer for the ipc |
| * @isp: the object |
| * |
| * Returns a pointer to the smack value |
| */ |
| static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp) |
| { |
| struct smack_known **blob = smack_ipc(isp); |
| |
| return *blob; |
| } |
| |
| /** |
| * smack_ipc_alloc_security - Set the security blob for ipc |
| * @isp: the object |
| * |
| * Returns 0 |
| */ |
| static int smack_ipc_alloc_security(struct kern_ipc_perm *isp) |
| { |
| struct smack_known **blob = smack_ipc(isp); |
| |
| *blob = smk_of_current(); |
| return 0; |
| } |
| |
| /** |
| * smk_curacc_shm : check if current has access on shm |
| * @isp : the object |
| * @access : access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smk_curacc_shm(struct kern_ipc_perm *isp, int access) |
| { |
| struct smack_known *ssp = smack_of_ipc(isp); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = isp->id; |
| #endif |
| rc = smk_curacc(ssp, access, &ad); |
| rc = smk_bu_current("shm", ssp, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_shm_associate - Smack access check for shm |
| * @isp: the object |
| * @shmflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(shmflg); |
| return smk_curacc_shm(isp, may); |
| } |
| |
| /** |
| * smack_shm_shmctl - Smack access check for shm |
| * @isp: the object |
| * @cmd: what it wants to do |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case IPC_STAT: |
| case SHM_STAT: |
| case SHM_STAT_ANY: |
| may = MAY_READ; |
| break; |
| case IPC_SET: |
| case SHM_LOCK: |
| case SHM_UNLOCK: |
| case IPC_RMID: |
| may = MAY_READWRITE; |
| break; |
| case IPC_INFO: |
| case SHM_INFO: |
| /* |
| * System level information. |
| */ |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| return smk_curacc_shm(isp, may); |
| } |
| |
| /** |
| * smack_shm_shmat - Smack access for shmat |
| * @isp: the object |
| * @shmaddr: unused |
| * @shmflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr, |
| int shmflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(shmflg); |
| return smk_curacc_shm(isp, may); |
| } |
| |
| /** |
| * smk_curacc_sem : check if current has access on sem |
| * @isp : the object |
| * @access : access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smk_curacc_sem(struct kern_ipc_perm *isp, int access) |
| { |
| struct smack_known *ssp = smack_of_ipc(isp); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = isp->id; |
| #endif |
| rc = smk_curacc(ssp, access, &ad); |
| rc = smk_bu_current("sem", ssp, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_sem_associate - Smack access check for sem |
| * @isp: the object |
| * @semflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(semflg); |
| return smk_curacc_sem(isp, may); |
| } |
| |
| /** |
| * smack_sem_semctl - Smack access check for sem |
| * @isp: the object |
| * @cmd: what it wants to do |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case GETPID: |
| case GETNCNT: |
| case GETZCNT: |
| case GETVAL: |
| case GETALL: |
| case IPC_STAT: |
| case SEM_STAT: |
| case SEM_STAT_ANY: |
| may = MAY_READ; |
| break; |
| case SETVAL: |
| case SETALL: |
| case IPC_RMID: |
| case IPC_SET: |
| may = MAY_READWRITE; |
| break; |
| case IPC_INFO: |
| case SEM_INFO: |
| /* |
| * System level information |
| */ |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| |
| return smk_curacc_sem(isp, may); |
| } |
| |
| /** |
| * smack_sem_semop - Smack checks of semaphore operations |
| * @isp: the object |
| * @sops: unused |
| * @nsops: unused |
| * @alter: unused |
| * |
| * Treated as read and write in all cases. |
| * |
| * Returns 0 if access is allowed, error code otherwise |
| */ |
| static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops, |
| unsigned nsops, int alter) |
| { |
| return smk_curacc_sem(isp, MAY_READWRITE); |
| } |
| |
| /** |
| * smk_curacc_msq : helper to check if current has access on msq |
| * @isp : the msq |
| * @access : access requested |
| * |
| * return 0 if current has access, error otherwise |
| */ |
| static int smk_curacc_msq(struct kern_ipc_perm *isp, int access) |
| { |
| struct smack_known *msp = smack_of_ipc(isp); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = isp->id; |
| #endif |
| rc = smk_curacc(msp, access, &ad); |
| rc = smk_bu_current("msq", msp, access, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_msg_queue_associate - Smack access check for msg_queue |
| * @isp: the object |
| * @msqflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(msqflg); |
| return smk_curacc_msq(isp, may); |
| } |
| |
| /** |
| * smack_msg_queue_msgctl - Smack access check for msg_queue |
| * @isp: the object |
| * @cmd: what it wants to do |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd) |
| { |
| int may; |
| |
| switch (cmd) { |
| case IPC_STAT: |
| case MSG_STAT: |
| case MSG_STAT_ANY: |
| may = MAY_READ; |
| break; |
| case IPC_SET: |
| case IPC_RMID: |
| may = MAY_READWRITE; |
| break; |
| case IPC_INFO: |
| case MSG_INFO: |
| /* |
| * System level information |
| */ |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| |
| return smk_curacc_msq(isp, may); |
| } |
| |
| /** |
| * smack_msg_queue_msgsnd - Smack access check for msg_queue |
| * @isp: the object |
| * @msg: unused |
| * @msqflg: access requested |
| * |
| * Returns 0 if current has the requested access, error code otherwise |
| */ |
| static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg, |
| int msqflg) |
| { |
| int may; |
| |
| may = smack_flags_to_may(msqflg); |
| return smk_curacc_msq(isp, may); |
| } |
| |
| /** |
| * smack_msg_queue_msgrcv - Smack access check for msg_queue |
| * @isp: the object |
| * @msg: unused |
| * @target: unused |
| * @type: unused |
| * @mode: unused |
| * |
| * Returns 0 if current has read and write access, error code otherwise |
| */ |
| static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, |
| struct msg_msg *msg, |
| struct task_struct *target, long type, |
| int mode) |
| { |
| return smk_curacc_msq(isp, MAY_READWRITE); |
| } |
| |
| /** |
| * smack_ipc_permission - Smack access for ipc_permission() |
| * @ipp: the object permissions |
| * @flag: access requested |
| * |
| * Returns 0 if current has read and write access, error code otherwise |
| */ |
| static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) |
| { |
| struct smack_known **blob = smack_ipc(ipp); |
| struct smack_known *iskp = *blob; |
| int may = smack_flags_to_may(flag); |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC); |
| ad.a.u.ipc_id = ipp->id; |
| #endif |
| rc = smk_curacc(iskp, may, &ad); |
| rc = smk_bu_current("svipc", iskp, may, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_ipc_getsecid - Extract smack security id |
| * @ipp: the object permissions |
| * @secid: where result will be saved |
| */ |
| static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) |
| { |
| struct smack_known **blob = smack_ipc(ipp); |
| struct smack_known *iskp = *blob; |
| |
| *secid = iskp->smk_secid; |
| } |
| |
| /** |
| * smack_d_instantiate - Make sure the blob is correct on an inode |
| * @opt_dentry: dentry where inode will be attached |
| * @inode: the object |
| * |
| * Set the inode's security blob if it hasn't been done already. |
| */ |
| static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) |
| { |
| struct super_block *sbp; |
| struct superblock_smack *sbsp; |
| struct inode_smack *isp; |
| struct smack_known *skp; |
| struct smack_known *ckp = smk_of_current(); |
| struct smack_known *final; |
| char trattr[TRANS_TRUE_SIZE]; |
| int transflag = 0; |
| int rc; |
| struct dentry *dp; |
| |
| if (inode == NULL) |
| return; |
| |
| isp = smack_inode(inode); |
| |
| /* |
| * If the inode is already instantiated |
| * take the quick way out |
| */ |
| if (isp->smk_flags & SMK_INODE_INSTANT) |
| return; |
| |
| sbp = inode->i_sb; |
| sbsp = smack_superblock(sbp); |
| /* |
| * We're going to use the superblock default label |
| * if there's no label on the file. |
| */ |
| final = sbsp->smk_default; |
| |
| /* |
| * If this is the root inode the superblock |
| * may be in the process of initialization. |
| * If that is the case use the root value out |
| * of the superblock. |
| */ |
| if (opt_dentry->d_parent == opt_dentry) { |
| switch (sbp->s_magic) { |
| case CGROUP_SUPER_MAGIC: |
| case CGROUP2_SUPER_MAGIC: |
| /* |
| * The cgroup filesystem is never mounted, |
| * so there's no opportunity to set the mount |
| * options. |
| */ |
| sbsp->smk_root = &smack_known_star; |
| sbsp->smk_default = &smack_known_star; |
| isp->smk_inode = sbsp->smk_root; |
| break; |
| case TMPFS_MAGIC: |
| /* |
| * What about shmem/tmpfs anonymous files with dentry |
| * obtained from d_alloc_pseudo()? |
| */ |
| isp->smk_inode = smk_of_current(); |
| break; |
| case PIPEFS_MAGIC: |
| isp->smk_inode = smk_of_current(); |
| break; |
| case SOCKFS_MAGIC: |
| /* |
| * Socket access is controlled by the socket |
| * structures associated with the task involved. |
| */ |
| isp->smk_inode = &smack_known_star; |
| break; |
| default: |
| isp->smk_inode = sbsp->smk_root; |
| break; |
| } |
| isp->smk_flags |= SMK_INODE_INSTANT; |
| return; |
| } |
| |
| /* |
| * This is pretty hackish. |
| * Casey says that we shouldn't have to do |
| * file system specific code, but it does help |
| * with keeping it simple. |
| */ |
| switch (sbp->s_magic) { |
| case SMACK_MAGIC: |
| case CGROUP_SUPER_MAGIC: |
| case CGROUP2_SUPER_MAGIC: |
| /* |
| * Casey says that it's a little embarrassing |
| * that the smack file system doesn't do |
| * extended attributes. |
| * |
| * Cgroupfs is special |
| */ |
| final = &smack_known_star; |
| break; |
| case DEVPTS_SUPER_MAGIC: |
| /* |
| * devpts seems content with the label of the task. |
| * Programs that change smack have to treat the |
| * pty with respect. |
| */ |
| final = ckp; |
| break; |
| case PROC_SUPER_MAGIC: |
| /* |
| * Casey says procfs appears not to care. |
| * The superblock default suffices. |
| */ |
| break; |
| case TMPFS_MAGIC: |
| /* |
| * Device labels should come from the filesystem, |
| * but watch out, because they're volitile, |
| * getting recreated on every reboot. |
| */ |
| final = &smack_known_star; |
| /* |
| * If a smack value has been set we want to use it, |
| * but since tmpfs isn't giving us the opportunity |
| * to set mount options simulate setting the |
| * superblock default. |
| */ |
| fallthrough; |
| default: |
| /* |
| * This isn't an understood special case. |
| * Get the value from the xattr. |
| */ |
| |
| /* |
| * UNIX domain sockets use lower level socket data. |
| */ |
| if (S_ISSOCK(inode->i_mode)) { |
| final = &smack_known_star; |
| break; |
| } |
| /* |
| * No xattr support means, alas, no SMACK label. |
| * Use the aforeapplied default. |
| * It would be curious if the label of the task |
| * does not match that assigned. |
| */ |
| if (!(inode->i_opflags & IOP_XATTR)) |
| break; |
| /* |
| * Get the dentry for xattr. |
| */ |
| dp = dget(opt_dentry); |
| skp = smk_fetch(XATTR_NAME_SMACK, inode, dp); |
| if (!IS_ERR_OR_NULL(skp)) |
| final = skp; |
| |
| /* |
| * Transmuting directory |
| */ |
| if (S_ISDIR(inode->i_mode)) { |
| /* |
| * If this is a new directory and the label was |
| * transmuted when the inode was initialized |
| * set the transmute attribute on the directory |
| * and mark the inode. |
| * |
| * If there is a transmute attribute on the |
| * directory mark the inode. |
| */ |
| if (isp->smk_flags & SMK_INODE_CHANGED) { |
| isp->smk_flags &= ~SMK_INODE_CHANGED; |
| rc = __vfs_setxattr(&init_user_ns, dp, inode, |
| XATTR_NAME_SMACKTRANSMUTE, |
| TRANS_TRUE, TRANS_TRUE_SIZE, |
| 0); |
| } else { |
| rc = __vfs_getxattr(dp, inode, |
| XATTR_NAME_SMACKTRANSMUTE, trattr, |
| TRANS_TRUE_SIZE); |
| if (rc >= 0 && strncmp(trattr, TRANS_TRUE, |
| TRANS_TRUE_SIZE) != 0) |
| rc = -EINVAL; |
| } |
| if (rc >= 0) |
| transflag = SMK_INODE_TRANSMUTE; |
| } |
| /* |
| * Don't let the exec or mmap label be "*" or "@". |
| */ |
| skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp); |
| if (IS_ERR(skp) || skp == &smack_known_star || |
| skp == &smack_known_web) |
| skp = NULL; |
| isp->smk_task = skp; |
| |
| skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp); |
| if (IS_ERR(skp) || skp == &smack_known_star || |
| skp == &smack_known_web) |
| skp = NULL; |
| isp->smk_mmap = skp; |
| |
| dput(dp); |
| break; |
| } |
| |
| if (final == NULL) |
| isp->smk_inode = ckp; |
| else |
| isp->smk_inode = final; |
| |
| isp->smk_flags |= (SMK_INODE_INSTANT | transflag); |
| |
| return; |
| } |
| |
| /** |
| * smack_getprocattr - Smack process attribute access |
| * @p: the object task |
| * @name: the name of the attribute in /proc/.../attr |
| * @value: where to put the result |
| * |
| * Places a copy of the task Smack into value |
| * |
| * Returns the length of the smack label or an error code |
| */ |
| static int smack_getprocattr(struct task_struct *p, char *name, char **value) |
| { |
| struct smack_known *skp = smk_of_task_struct_obj(p); |
| char *cp; |
| int slen; |
| |
| if (strcmp(name, "current") != 0) |
| return -EINVAL; |
| |
| cp = kstrdup(skp->smk_known, GFP_KERNEL); |
| if (cp == NULL) |
| return -ENOMEM; |
| |
| slen = strlen(cp); |
| *value = cp; |
| return slen; |
| } |
| |
| /** |
| * smack_setprocattr - Smack process attribute setting |
| * @name: the name of the attribute in /proc/.../attr |
| * @value: the value to set |
| * @size: the size of the value |
| * |
| * Sets the Smack value of the task. Only setting self |
| * is permitted and only with privilege |
| * |
| * Returns the length of the smack label or an error code |
| */ |
| static int smack_setprocattr(const char *name, void *value, size_t size) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct cred *new; |
| struct smack_known *skp; |
| struct smack_known_list_elem *sklep; |
| int rc; |
| |
| if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel)) |
| return -EPERM; |
| |
| if (value == NULL || size == 0 || size >= SMK_LONGLABEL) |
| return -EINVAL; |
| |
| if (strcmp(name, "current") != 0) |
| return -EINVAL; |
| |
| skp = smk_import_entry(value, size); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| |
| /* |
| * No process is ever allowed the web ("@") label |
| * and the star ("*") label. |
| */ |
| if (skp == &smack_known_web || skp == &smack_known_star) |
| return -EINVAL; |
| |
| if (!smack_privileged(CAP_MAC_ADMIN)) { |
| rc = -EPERM; |
| list_for_each_entry(sklep, &tsp->smk_relabel, list) |
| if (sklep->smk_label == skp) { |
| rc = 0; |
| break; |
| } |
| if (rc) |
| return rc; |
| } |
| |
| new = prepare_creds(); |
| if (new == NULL) |
| return -ENOMEM; |
| |
| tsp = smack_cred(new); |
| tsp->smk_task = skp; |
| /* |
| * process can change its label only once |
| */ |
| smk_destroy_label_list(&tsp->smk_relabel); |
| |
| commit_creds(new); |
| return size; |
| } |
| |
| /** |
| * smack_unix_stream_connect - Smack access on UDS |
| * @sock: one sock |
| * @other: the other sock |
| * @newsk: unused |
| * |
| * Return 0 if a subject with the smack of sock could access |
| * an object with the smack of other, otherwise an error code |
| */ |
| static int smack_unix_stream_connect(struct sock *sock, |
| struct sock *other, struct sock *newsk) |
| { |
| struct smack_known *skp; |
| struct smack_known *okp; |
| struct socket_smack *ssp = sock->sk_security; |
| struct socket_smack *osp = other->sk_security; |
| struct socket_smack *nsp = newsk->sk_security; |
| struct smk_audit_info ad; |
| int rc = 0; |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| |
| if (!smack_privileged(CAP_MAC_OVERRIDE)) { |
| skp = ssp->smk_out; |
| okp = osp->smk_in; |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| smk_ad_setfield_u_net_sk(&ad, other); |
| #endif |
| rc = smk_access(skp, okp, MAY_WRITE, &ad); |
| rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc); |
| if (rc == 0) { |
| okp = osp->smk_out; |
| skp = ssp->smk_in; |
| rc = smk_access(okp, skp, MAY_WRITE, &ad); |
| rc = smk_bu_note("UDS connect", okp, skp, |
| MAY_WRITE, rc); |
| } |
| } |
| |
| /* |
| * Cross reference the peer labels for SO_PEERSEC. |
| */ |
| if (rc == 0) { |
| nsp->smk_packet = ssp->smk_out; |
| ssp->smk_packet = osp->smk_out; |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_unix_may_send - Smack access on UDS |
| * @sock: one socket |
| * @other: the other socket |
| * |
| * Return 0 if a subject with the smack of sock could access |
| * an object with the smack of other, otherwise an error code |
| */ |
| static int smack_unix_may_send(struct socket *sock, struct socket *other) |
| { |
| struct socket_smack *ssp = sock->sk->sk_security; |
| struct socket_smack *osp = other->sk->sk_security; |
| struct smk_audit_info ad; |
| int rc; |
| |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| smk_ad_setfield_u_net_sk(&ad, other->sk); |
| #endif |
| |
| if (smack_privileged(CAP_MAC_OVERRIDE)) |
| return 0; |
| |
| rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad); |
| rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc); |
| return rc; |
| } |
| |
| /** |
| * smack_socket_sendmsg - Smack check based on destination host |
| * @sock: the socket |
| * @msg: the message |
| * @size: the size of the message |
| * |
| * Return 0 if the current subject can write to the destination host. |
| * For IPv4 this is only a question if the destination is a single label host. |
| * For IPv6 this is a check against the label of the port. |
| */ |
| static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, |
| int size) |
| { |
| struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; |
| #if IS_ENABLED(CONFIG_IPV6) |
| struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name; |
| #endif |
| #ifdef SMACK_IPV6_SECMARK_LABELING |
| struct socket_smack *ssp = sock->sk->sk_security; |
| struct smack_known *rsp; |
| #endif |
| int rc = 0; |
| |
| /* |
| * Perfectly reasonable for this to be NULL |
| */ |
| if (sip == NULL) |
| return 0; |
| |
| switch (sock->sk->sk_family) { |
| case AF_INET: |
| if (msg->msg_namelen < sizeof(struct sockaddr_in) || |
| sip->sin_family != AF_INET) |
| return -EINVAL; |
| rc = smk_ipv4_check(sock->sk, sip); |
| break; |
| #if IS_ENABLED(CONFIG_IPV6) |
| case AF_INET6: |
| if (msg->msg_namelen < SIN6_LEN_RFC2133 || |
| sap->sin6_family != AF_INET6) |
| return -EINVAL; |
| #ifdef SMACK_IPV6_SECMARK_LABELING |
| rsp = smack_ipv6host_label(sap); |
| if (rsp != NULL) |
| rc = smk_ipv6_check(ssp->smk_out, rsp, sap, |
| SMK_CONNECTING); |
| #endif |
| #ifdef SMACK_IPV6_PORT_LABELING |
| rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING); |
| #endif |
| #endif /* IS_ENABLED(CONFIG_IPV6) */ |
| break; |
| } |
| return rc; |
| } |
| |
| /** |
| * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack |
| * @sap: netlabel secattr |
| * @ssp: socket security information |
| * |
| * Returns a pointer to a Smack label entry found on the label list. |
| */ |
| static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap, |
| struct socket_smack *ssp) |
| { |
| struct smack_known *skp; |
| int found = 0; |
| int acat; |
| int kcat; |
| |
| /* |
| * Netlabel found it in the cache. |
| */ |
| if ((sap->flags & NETLBL_SECATTR_CACHE) != 0) |
| return (struct smack_known *)sap->cache->data; |
| |
| if ((sap->flags & NETLBL_SECATTR_SECID) != 0) |
| /* |
| * Looks like a fallback, which gives us a secid. |
| */ |
| return smack_from_secid(sap->attr.secid); |
| |
| if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { |
| /* |
| * Looks like a CIPSO packet. |
| * If there are flags but no level netlabel isn't |
| * behaving the way we expect it to. |
| * |
| * Look it up in the label table |
| * Without guidance regarding the smack value |
| * for the packet fall back on the network |
| * ambient value. |
| */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(skp, &smack_known_list, list) { |
| if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl) |
| continue; |
| /* |
| * Compare the catsets. Use the netlbl APIs. |
| */ |
| if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) { |
| if ((skp->smk_netlabel.flags & |
| NETLBL_SECATTR_MLS_CAT) == 0) |
| found = 1; |
| break; |
| } |
| for (acat = -1, kcat = -1; acat == kcat; ) { |
| acat = netlbl_catmap_walk(sap->attr.mls.cat, |
| acat + 1); |
| kcat = netlbl_catmap_walk( |
| skp->smk_netlabel.attr.mls.cat, |
| kcat + 1); |
| if (acat < 0 || kcat < 0) |
| break; |
| } |
| if (acat == kcat) { |
| found = 1; |
| break; |
| } |
| } |
| rcu_read_unlock(); |
| |
| if (found) |
| return skp; |
| |
| if (ssp != NULL && ssp->smk_in == &smack_known_star) |
| return &smack_known_web; |
| return &smack_known_star; |
| } |
| /* |
| * Without guidance regarding the smack value |
| * for the packet fall back on the network |
| * ambient value. |
| */ |
| return smack_net_ambient; |
| } |
| |
| #if IS_ENABLED(CONFIG_IPV6) |
| static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip) |
| { |
| u8 nexthdr; |
| int offset; |
| int proto = -EINVAL; |
| struct ipv6hdr _ipv6h; |
| struct ipv6hdr *ip6; |
| __be16 frag_off; |
| struct tcphdr _tcph, *th; |
| struct udphdr _udph, *uh; |
| struct dccp_hdr _dccph, *dh; |
| |
| sip->sin6_port = 0; |
| |
| offset = skb_network_offset(skb); |
| ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); |
| if (ip6 == NULL) |
| return -EINVAL; |
| sip->sin6_addr = ip6->saddr; |
| |
| nexthdr = ip6->nexthdr; |
| offset += sizeof(_ipv6h); |
| offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); |
| if (offset < 0) |
| return -EINVAL; |
| |
| proto = nexthdr; |
| switch (proto) { |
| case IPPROTO_TCP: |
| th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); |
| if (th != NULL) |
| sip->sin6_port = th->source; |
| break; |
| case IPPROTO_UDP: |
| case IPPROTO_UDPLITE: |
| uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); |
| if (uh != NULL) |
| sip->sin6_port = uh->source; |
| break; |
| case IPPROTO_DCCP: |
| dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); |
| if (dh != NULL) |
| sip->sin6_port = dh->dccph_sport; |
| break; |
| } |
| return proto; |
| } |
| #endif /* CONFIG_IPV6 */ |
| |
| /** |
| * smack_from_skb - Smack data from the secmark in an skb |
| * @skb: packet |
| * |
| * Returns smack_known of the secmark or NULL if that won't work. |
| */ |
| #ifdef CONFIG_NETWORK_SECMARK |
| static struct smack_known *smack_from_skb(struct sk_buff *skb) |
| { |
| if (skb == NULL || skb->secmark == 0) |
| return NULL; |
| |
| return smack_from_secid(skb->secmark); |
| } |
| #else |
| static inline struct smack_known *smack_from_skb(struct sk_buff *skb) |
| { |
| return NULL; |
| } |
| #endif |
| |
| /** |
| * smack_from_netlbl - Smack data from the IP options in an skb |
| * @sk: socket data came in on |
| * @family: address family |
| * @skb: packet |
| * |
| * Find the Smack label in the IP options. If it hasn't been |
| * added to the netlabel cache, add it here. |
| * |
| * Returns smack_known of the IP options or NULL if that won't work. |
| */ |
| static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family, |
| struct sk_buff *skb) |
| { |
| struct netlbl_lsm_secattr secattr; |
| struct socket_smack *ssp = NULL; |
| struct smack_known *skp = NULL; |
| |
| netlbl_secattr_init(&secattr); |
| |
| if (sk) |
| ssp = sk->sk_security; |
| |
| if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) { |
| skp = smack_from_secattr(&secattr, ssp); |
| if (secattr.flags & NETLBL_SECATTR_CACHEABLE) |
| netlbl_cache_add(skb, family, &skp->smk_netlabel); |
| } |
| |
| netlbl_secattr_destroy(&secattr); |
| |
| return skp; |
| } |
| |
| /** |
| * smack_socket_sock_rcv_skb - Smack packet delivery access check |
| * @sk: socket |
| * @skb: packet |
| * |
| * Returns 0 if the packet should be delivered, an error code otherwise |
| */ |
| static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) |
| { |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp = NULL; |
| int rc = 0; |
| struct smk_audit_info ad; |
| u16 family = sk->sk_family; |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| #if IS_ENABLED(CONFIG_IPV6) |
| struct sockaddr_in6 sadd; |
| int proto; |
| |
| if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) |
| family = PF_INET; |
| #endif /* CONFIG_IPV6 */ |
| |
| switch (family) { |
| case PF_INET: |
| /* |
| * If there is a secmark use it rather than the CIPSO label. |
| * If there is no secmark fall back to CIPSO. |
| * The secmark is assumed to reflect policy better. |
| */ |
| skp = smack_from_skb(skb); |
| if (skp == NULL) { |
| skp = smack_from_netlbl(sk, family, skb); |
| if (skp == NULL) |
| skp = smack_net_ambient; |
| } |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = family; |
| ad.a.u.net->netif = skb->skb_iif; |
| ipv4_skb_to_auditdata(skb, &ad.a, NULL); |
| #endif |
| /* |
| * Receiving a packet requires that the other end |
| * be able to write here. Read access is not required. |
| * This is the simplist possible security model |
| * for networking. |
| */ |
| rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in, |
| MAY_WRITE, rc); |
| if (rc != 0) |
| netlbl_skbuff_err(skb, family, rc, 0); |
| break; |
| #if IS_ENABLED(CONFIG_IPV6) |
| case PF_INET6: |
| proto = smk_skb_to_addr_ipv6(skb, &sadd); |
| if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE && |
| proto != IPPROTO_TCP && proto != IPPROTO_DCCP) |
| break; |
| #ifdef SMACK_IPV6_SECMARK_LABELING |
| skp = smack_from_skb(skb); |
| if (skp == NULL) { |
| if (smk_ipv6_localhost(&sadd)) |
| break; |
| skp = smack_ipv6host_label(&sadd); |
| if (skp == NULL) |
| skp = smack_net_ambient; |
| } |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = family; |
| ad.a.u.net->netif = skb->skb_iif; |
| ipv6_skb_to_auditdata(skb, &ad.a, NULL); |
| #endif /* CONFIG_AUDIT */ |
| rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in, |
| MAY_WRITE, rc); |
| #endif /* SMACK_IPV6_SECMARK_LABELING */ |
| #ifdef SMACK_IPV6_PORT_LABELING |
| rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING); |
| #endif /* SMACK_IPV6_PORT_LABELING */ |
| if (rc != 0) |
| icmpv6_send(skb, ICMPV6_DEST_UNREACH, |
| ICMPV6_ADM_PROHIBITED, 0); |
| break; |
| #endif /* CONFIG_IPV6 */ |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * smack_socket_getpeersec_stream - pull in packet label |
| * @sock: the socket |
| * @optval: user's destination |
| * @optlen: size thereof |
| * @len: max thereof |
| * |
| * returns zero on success, an error code otherwise |
| */ |
| static int smack_socket_getpeersec_stream(struct socket *sock, |
| char __user *optval, |
| int __user *optlen, unsigned len) |
| { |
| struct socket_smack *ssp; |
| char *rcp = ""; |
| int slen = 1; |
| int rc = 0; |
| |
| ssp = sock->sk->sk_security; |
| if (ssp->smk_packet != NULL) { |
| rcp = ssp->smk_packet->smk_known; |
| slen = strlen(rcp) + 1; |
| } |
| |
| if (slen > len) |
| rc = -ERANGE; |
| else if (copy_to_user(optval, rcp, slen) != 0) |
| rc = -EFAULT; |
| |
| if (put_user(slen, optlen) != 0) |
| rc = -EFAULT; |
| |
| return rc; |
| } |
| |
| |
| /** |
| * smack_socket_getpeersec_dgram - pull in packet label |
| * @sock: the peer socket |
| * @skb: packet data |
| * @secid: pointer to where to put the secid of the packet |
| * |
| * Sets the netlabel socket state on sk from parent |
| */ |
| static int smack_socket_getpeersec_dgram(struct socket *sock, |
| struct sk_buff *skb, u32 *secid) |
| |
| { |
| struct socket_smack *ssp = NULL; |
| struct smack_known *skp; |
| struct sock *sk = NULL; |
| int family = PF_UNSPEC; |
| u32 s = 0; /* 0 is the invalid secid */ |
| |
| if (skb != NULL) { |
| if (skb->protocol == htons(ETH_P_IP)) |
| family = PF_INET; |
| #if IS_ENABLED(CONFIG_IPV6) |
| else if (skb->protocol == htons(ETH_P_IPV6)) |
| family = PF_INET6; |
| #endif /* CONFIG_IPV6 */ |
| } |
| if (family == PF_UNSPEC && sock != NULL) |
| family = sock->sk->sk_family; |
| |
| switch (family) { |
| case PF_UNIX: |
| ssp = sock->sk->sk_security; |
| s = ssp->smk_out->smk_secid; |
| break; |
| case PF_INET: |
| skp = smack_from_skb(skb); |
| if (skp) { |
| s = skp->smk_secid; |
| break; |
| } |
| /* |
| * Translate what netlabel gave us. |
| */ |
| if (sock != NULL) |
| sk = sock->sk; |
| skp = smack_from_netlbl(sk, family, skb); |
| if (skp != NULL) |
| s = skp->smk_secid; |
| break; |
| case PF_INET6: |
| #ifdef SMACK_IPV6_SECMARK_LABELING |
| skp = smack_from_skb(skb); |
| if (skp) |
| s = skp->smk_secid; |
| #endif |
| break; |
| } |
| *secid = s; |
| if (s == 0) |
| return -EINVAL; |
| return 0; |
| } |
| |
| /** |
| * smack_sock_graft - Initialize a newly created socket with an existing sock |
| * @sk: child sock |
| * @parent: parent socket |
| * |
| * Set the smk_{in,out} state of an existing sock based on the process that |
| * is creating the new socket. |
| */ |
| static void smack_sock_graft(struct sock *sk, struct socket *parent) |
| { |
| struct socket_smack *ssp; |
| struct smack_known *skp = smk_of_current(); |
| |
| if (sk == NULL || |
| (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) |
| return; |
| |
| ssp = sk->sk_security; |
| ssp->smk_in = skp; |
| ssp->smk_out = skp; |
| /* cssp->smk_packet is already set in smack_inet_csk_clone() */ |
| } |
| |
| /** |
| * smack_inet_conn_request - Smack access check on connect |
| * @sk: socket involved |
| * @skb: packet |
| * @req: unused |
| * |
| * Returns 0 if a task with the packet label could write to |
| * the socket, otherwise an error code |
| */ |
| static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, |
| struct request_sock *req) |
| { |
| u16 family = sk->sk_family; |
| struct smack_known *skp; |
| struct socket_smack *ssp = sk->sk_security; |
| struct sockaddr_in addr; |
| struct iphdr *hdr; |
| struct smack_known *hskp; |
| int rc; |
| struct smk_audit_info ad; |
| #ifdef CONFIG_AUDIT |
| struct lsm_network_audit net; |
| #endif |
| |
| #if IS_ENABLED(CONFIG_IPV6) |
| if (family == PF_INET6) { |
| /* |
| * Handle mapped IPv4 packets arriving |
| * via IPv6 sockets. Don't set up netlabel |
| * processing on IPv6. |
| */ |
| if (skb->protocol == htons(ETH_P_IP)) |
| family = PF_INET; |
| else |
| return 0; |
| } |
| #endif /* CONFIG_IPV6 */ |
| |
| /* |
| * If there is a secmark use it rather than the CIPSO label. |
| * If there is no secmark fall back to CIPSO. |
| * The secmark is assumed to reflect policy better. |
| */ |
| skp = smack_from_skb(skb); |
| if (skp == NULL) { |
| skp = smack_from_netlbl(sk, family, skb); |
| if (skp == NULL) |
| skp = &smack_known_huh; |
| } |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net); |
| ad.a.u.net->family = family; |
| ad.a.u.net->netif = skb->skb_iif; |
| ipv4_skb_to_auditdata(skb, &ad.a, NULL); |
| #endif |
| /* |
| * Receiving a packet requires that the other end be able to write |
| * here. Read access is not required. |
| */ |
| rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad); |
| rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc); |
| if (rc != 0) |
| return rc; |
| |
| /* |
| * Save the peer's label in the request_sock so we can later setup |
| * smk_packet in the child socket so that SO_PEERCRED can report it. |
| */ |
| req->peer_secid = skp->smk_secid; |
| |
| /* |
| * We need to decide if we want to label the incoming connection here |
| * if we do we only need to label the request_sock and the stack will |
| * propagate the wire-label to the sock when it is created. |
| */ |
| hdr = ip_hdr(skb); |
| addr.sin_addr.s_addr = hdr->saddr; |
| rcu_read_lock(); |
| hskp = smack_ipv4host_label(&addr); |
| rcu_read_unlock(); |
| |
| if (hskp == NULL) |
| rc = netlbl_req_setattr(req, &skp->smk_netlabel); |
| else |
| netlbl_req_delattr(req); |
| |
| return rc; |
| } |
| |
| /** |
| * smack_inet_csk_clone - Copy the connection information to the new socket |
| * @sk: the new socket |
| * @req: the connection's request_sock |
| * |
| * Transfer the connection's peer label to the newly created socket. |
| */ |
| static void smack_inet_csk_clone(struct sock *sk, |
| const struct request_sock *req) |
| { |
| struct socket_smack *ssp = sk->sk_security; |
| struct smack_known *skp; |
| |
| if (req->peer_secid != 0) { |
| skp = smack_from_secid(req->peer_secid); |
| ssp->smk_packet = skp; |
| } else |
| ssp->smk_packet = NULL; |
| } |
| |
| /* |
| * Key management security hooks |
| * |
| * Casey has not tested key support very heavily. |
| * The permission check is most likely too restrictive. |
| * If you care about keys please have a look. |
| */ |
| #ifdef CONFIG_KEYS |
| |
| /** |
| * smack_key_alloc - Set the key security blob |
| * @key: object |
| * @cred: the credentials to use |
| * @flags: unused |
| * |
| * No allocation required |
| * |
| * Returns 0 |
| */ |
| static int smack_key_alloc(struct key *key, const struct cred *cred, |
| unsigned long flags) |
| { |
| struct smack_known *skp = smk_of_task(smack_cred(cred)); |
| |
| key->security = skp; |
| return 0; |
| } |
| |
| /** |
| * smack_key_free - Clear the key security blob |
| * @key: the object |
| * |
| * Clear the blob pointer |
| */ |
| static void smack_key_free(struct key *key) |
| { |
| key->security = NULL; |
| } |
| |
| /** |
| * smack_key_permission - Smack access on a key |
| * @key_ref: gets to the object |
| * @cred: the credentials to use |
| * @need_perm: requested key permission |
| * |
| * Return 0 if the task has read and write to the object, |
| * an error code otherwise |
| */ |
| static int smack_key_permission(key_ref_t key_ref, |
| const struct cred *cred, |
| enum key_need_perm need_perm) |
| { |
| struct key *keyp; |
| struct smk_audit_info ad; |
| struct smack_known *tkp = smk_of_task(smack_cred(cred)); |
| int request = 0; |
| int rc; |
| |
| /* |
| * Validate requested permissions |
| */ |
| switch (need_perm) { |
| case KEY_NEED_READ: |
| case KEY_NEED_SEARCH: |
| case KEY_NEED_VIEW: |
| request |= MAY_READ; |
| break; |
| case KEY_NEED_WRITE: |
| case KEY_NEED_LINK: |
| case KEY_NEED_SETATTR: |
| request |= MAY_WRITE; |
| break; |
| case KEY_NEED_UNSPECIFIED: |
| case KEY_NEED_UNLINK: |
| case KEY_SYSADMIN_OVERRIDE: |
| case KEY_AUTHTOKEN_OVERRIDE: |
| case KEY_DEFER_PERM_CHECK: |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| |
| keyp = key_ref_to_ptr(key_ref); |
| if (keyp == NULL) |
| return -EINVAL; |
| /* |
| * If the key hasn't been initialized give it access so that |
| * it may do so. |
| */ |
| if (keyp->security == NULL) |
| return 0; |
| /* |
| * This should not occur |
| */ |
| if (tkp == NULL) |
| return -EACCES; |
| |
| if (smack_privileged(CAP_MAC_OVERRIDE)) |
| return 0; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); |
| ad.a.u.key_struct.key = keyp->serial; |
| ad.a.u.key_struct.key_desc = keyp->description; |
| #endif |
| rc = smk_access(tkp, keyp->security, request, &ad); |
| rc = smk_bu_note("key access", tkp, keyp->security, request, rc); |
| return rc; |
| } |
| |
| /* |
| * smack_key_getsecurity - Smack label tagging the key |
| * @key points to the key to be queried |
| * @_buffer points to a pointer that should be set to point to the |
| * resulting string (if no label or an error occurs). |
| * Return the length of the string (including terminating NUL) or -ve if |
| * an error. |
| * May also return 0 (and a NULL buffer pointer) if there is no label. |
| */ |
| static int smack_key_getsecurity(struct key *key, char **_buffer) |
| { |
| struct smack_known *skp = key->security; |
| size_t length; |
| char *copy; |
| |
| if (key->security == NULL) { |
| *_buffer = NULL; |
| return 0; |
| } |
| |
| copy = kstrdup(skp->smk_known, GFP_KERNEL); |
| if (copy == NULL) |
| return -ENOMEM; |
| length = strlen(copy) + 1; |
| |
| *_buffer = copy; |
| return length; |
| } |
| |
| |
| #ifdef CONFIG_KEY_NOTIFICATIONS |
| /** |
| * smack_watch_key - Smack access to watch a key for notifications. |
| * @key: The key to be watched |
| * |
| * Return 0 if the @watch->cred has permission to read from the key object and |
| * an error otherwise. |
| */ |
| static int smack_watch_key(struct key *key) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *tkp = smk_of_current(); |
| int rc; |
| |
| if (key == NULL) |
| return -EINVAL; |
| /* |
| * If the key hasn't been initialized give it access so that |
| * it may do so. |
| */ |
| if (key->security == NULL) |
| return 0; |
| /* |
| * This should not occur |
| */ |
| if (tkp == NULL) |
| return -EACCES; |
| |
| if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) |
| return 0; |
| |
| #ifdef CONFIG_AUDIT |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); |
| ad.a.u.key_struct.key = key->serial; |
| ad.a.u.key_struct.key_desc = key->description; |
| #endif |
| rc = smk_access(tkp, key->security, MAY_READ, &ad); |
| rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc); |
| return rc; |
| } |
| #endif /* CONFIG_KEY_NOTIFICATIONS */ |
| #endif /* CONFIG_KEYS */ |
| |
| #ifdef CONFIG_WATCH_QUEUE |
| /** |
| * smack_post_notification - Smack access to post a notification to a queue |
| * @w_cred: The credentials of the watcher. |
| * @cred: The credentials of the event source (may be NULL). |
| * @n: The notification message to be posted. |
| */ |
| static int smack_post_notification(const struct cred *w_cred, |
| const struct cred *cred, |
| struct watch_notification *n) |
| { |
| struct smk_audit_info ad; |
| struct smack_known *subj, *obj; |
| int rc; |
| |
| /* Always let maintenance notifications through. */ |
| if (n->type == WATCH_TYPE_META) |
| return 0; |
| |
| if (!cred) |
| return 0; |
| subj = smk_of_task(smack_cred(cred)); |
| obj = smk_of_task(smack_cred(w_cred)); |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION); |
| rc = smk_access(subj, obj, MAY_WRITE, &ad); |
| rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc); |
| return rc; |
| } |
| #endif /* CONFIG_WATCH_QUEUE */ |
| |
| /* |
| * Smack Audit hooks |
| * |
| * Audit requires a unique representation of each Smack specific |
| * rule. This unique representation is used to distinguish the |
| * object to be audited from remaining kernel objects and also |
| * works as a glue between the audit hooks. |
| * |
| * Since repository entries are added but never deleted, we'll use |
| * the smack_known label address related to the given audit rule as |
| * the needed unique representation. This also better fits the smack |
| * model where nearly everything is a label. |
| */ |
| #ifdef CONFIG_AUDIT |
| |
| /** |
| * smack_audit_rule_init - Initialize a smack audit rule |
| * @field: audit rule fields given from user-space (audit.h) |
| * @op: required testing operator (=, !=, >, <, ...) |
| * @rulestr: smack label to be audited |
| * @vrule: pointer to save our own audit rule representation |
| * |
| * Prepare to audit cases where (@field @op @rulestr) is true. |
| * The label to be audited is created if necessay. |
| */ |
| static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) |
| { |
| struct smack_known *skp; |
| char **rule = (char **)vrule; |
| *rule = NULL; |
| |
| if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) |
| return -EINVAL; |
| |
| if (op != Audit_equal && op != Audit_not_equal) |
| return -EINVAL; |
| |
| skp = smk_import_entry(rulestr, 0); |
| if (IS_ERR(skp)) |
| return PTR_ERR(skp); |
| |
| *rule = skp->smk_known; |
| |
| return 0; |
| } |
| |
| /** |
| * smack_audit_rule_known - Distinguish Smack audit rules |
| * @krule: rule of interest, in Audit kernel representation format |
| * |
| * This is used to filter Smack rules from remaining Audit ones. |
| * If it's proved that this rule belongs to us, the |
| * audit_rule_match hook will be called to do the final judgement. |
| */ |
| static int smack_audit_rule_known(struct audit_krule *krule) |
| { |
| struct audit_field *f; |
| int i; |
| |
| for (i = 0; i < krule->field_count; i++) { |
| f = &krule->fields[i]; |
| |
| if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * smack_audit_rule_match - Audit given object ? |
| * @secid: security id for identifying the object to test |
| * @field: audit rule flags given from user-space |
| * @op: required testing operator |
| * @vrule: smack internal rule presentation |
| * |
| * The core Audit hook. It's used to take the decision of |
| * whether to audit or not to audit a given object. |
| */ |
| static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule) |
| { |
| struct smack_known *skp; |
| char *rule = vrule; |
| |
| if (unlikely(!rule)) { |
| WARN_ONCE(1, "Smack: missing rule\n"); |
| return -ENOENT; |
| } |
| |
| if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) |
| return 0; |
| |
| skp = smack_from_secid(secid); |
| |
| /* |
| * No need to do string comparisons. If a match occurs, |
| * both pointers will point to the same smack_known |
| * label. |
| */ |
| if (op == Audit_equal) |
| return (rule == skp->smk_known); |
| if (op == Audit_not_equal) |
| return (rule != skp->smk_known); |
| |
| return 0; |
| } |
| |
| /* |
| * There is no need for a smack_audit_rule_free hook. |
| * No memory was allocated. |
| */ |
| |
| #endif /* CONFIG_AUDIT */ |
| |
| /** |
| * smack_ismaclabel - check if xattr @name references a smack MAC label |
| * @name: Full xattr name to check. |
| */ |
| static int smack_ismaclabel(const char *name) |
| { |
| return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); |
| } |
| |
| |
| /** |
| * smack_secid_to_secctx - return the smack label for a secid |
| * @secid: incoming integer |
| * @secdata: destination |
| * @seclen: how long it is |
| * |
| * Exists for networking code. |
| */ |
| static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) |
| { |
| struct smack_known *skp = smack_from_secid(secid); |
| |
| if (secdata) |
| *secdata = skp->smk_known; |
| *seclen = strlen(skp->smk_known); |
| return 0; |
| } |
| |
| /** |
| * smack_secctx_to_secid - return the secid for a smack label |
| * @secdata: smack label |
| * @seclen: how long result is |
| * @secid: outgoing integer |
| * |
| * Exists for audit and networking code. |
| */ |
| static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) |
| { |
| struct smack_known *skp = smk_find_entry(secdata); |
| |
| if (skp) |
| *secid = skp->smk_secid; |
| else |
| *secid = 0; |
| return 0; |
| } |
| |
| /* |
| * There used to be a smack_release_secctx hook |
| * that did nothing back when hooks were in a vector. |
| * Now that there's a list such a hook adds cost. |
| */ |
| |
| static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) |
| { |
| return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, |
| ctxlen, 0); |
| } |
| |
| static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) |
| { |
| return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SMACK, |
| ctx, ctxlen, 0); |
| } |
| |
| static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) |
| { |
| struct smack_known *skp = smk_of_inode(inode); |
| |
| *ctx = skp->smk_known; |
| *ctxlen = strlen(skp->smk_known); |
| return 0; |
| } |
| |
| static int smack_inode_copy_up(struct dentry *dentry, struct cred **new) |
| { |
| |
| struct task_smack *tsp; |
| struct smack_known *skp; |
| struct inode_smack *isp; |
| struct cred *new_creds = *new; |
| |
| if (new_creds == NULL) { |
| new_creds = prepare_creds(); |
| if (new_creds == NULL) |
| return -ENOMEM; |
| } |
| |
| tsp = smack_cred(new_creds); |
| |
| /* |
| * Get label from overlay inode and set it in create_sid |
| */ |
| isp = smack_inode(d_inode(dentry)); |
| skp = isp->smk_inode; |
| tsp->smk_task = skp; |
| *new = new_creds; |
| return 0; |
| } |
| |
| static int smack_inode_copy_up_xattr(const char *name) |
| { |
| /* |
| * Return 1 if this is the smack access Smack attribute. |
| */ |
| if (strcmp(name, XATTR_NAME_SMACK) == 0) |
| return 1; |
| |
| return -EOPNOTSUPP; |
| } |
| |
| static int smack_dentry_create_files_as(struct dentry *dentry, int mode, |
| struct qstr *name, |
| const struct cred *old, |
| struct cred *new) |
| { |
| struct task_smack *otsp = smack_cred(old); |
| struct task_smack *ntsp = smack_cred(new); |
| struct inode_smack *isp; |
| int may; |
| |
| /* |
| * Use the process credential unless all of |
| * the transmuting criteria are met |
| */ |
| ntsp->smk_task = otsp->smk_task; |
| |
| /* |
| * the attribute of the containing directory |
| */ |
| isp = smack_inode(d_inode(dentry->d_parent)); |
| |
| if (isp->smk_flags & SMK_INODE_TRANSMUTE) { |
| rcu_read_lock(); |
| may = smk_access_entry(otsp->smk_task->smk_known, |
| isp->smk_inode->smk_known, |
| &otsp->smk_task->smk_rules); |
| rcu_read_unlock(); |
| |
| /* |
| * If the directory is transmuting and the rule |
| * providing access is transmuting use the containing |
| * directory label instead of the process label. |
| */ |
| if (may > 0 && (may & MAY_TRANSMUTE)) |
| ntsp->smk_task = isp->smk_inode; |
| } |
| return 0; |
| } |
| |
| #ifdef CONFIG_IO_URING |
| /** |
| * smack_uring_override_creds - Is io_uring cred override allowed? |
| * @new: the target creds |
| * |
| * Check to see if the current task is allowed to override it's credentials |
| * to service an io_uring operation. |
| */ |
| static int smack_uring_override_creds(const struct cred *new) |
| { |
| struct task_smack *tsp = smack_cred(current_cred()); |
| struct task_smack *nsp = smack_cred(new); |
| |
| /* |
| * Allow the degenerate case where the new Smack value is |
| * the same as the current Smack value. |
| */ |
| if (tsp->smk_task == nsp->smk_task) |
| return 0; |
| |
| if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred())) |
| return 0; |
| |
| return -EPERM; |
| } |
| |
| /** |
| * smack_uring_sqpoll - check if a io_uring polling thread can be created |
| * |
| * Check to see if the current task is allowed to create a new io_uring |
| * kernel polling thread. |
| */ |
| static int smack_uring_sqpoll(void) |
| { |
| if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred())) |
| return 0; |
| |
| return -EPERM; |
| } |
| |
| /** |
| * smack_uring_cmd - check on file operations for io_uring |
| * @ioucmd: the command in question |
| * |
| * Make a best guess about whether a io_uring "command" should |
| * be allowed. Use the same logic used for determining if the |
| * file could be opened for read in the absence of better criteria. |
| */ |
| static int smack_uring_cmd(struct io_uring_cmd *ioucmd) |
| { |
| struct file *file = ioucmd->file; |
| struct smk_audit_info ad; |
| struct task_smack *tsp; |
| struct inode *inode; |
| int rc; |
| |
| if (!file) |
| return -EINVAL; |
| |
| tsp = smack_cred(file->f_cred); |
| inode = file_inode(file); |
| |
| smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH); |
| smk_ad_setfield_u_fs_path(&ad, file->f_path); |
| rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad); |
| rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc); |
| |
| return rc; |
| } |
| |
| #endif /* CONFIG_IO_URING */ |
| |
| struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { |
| .lbs_cred = sizeof(struct task_smack), |
| .lbs_file = sizeof(struct smack_known *), |
| .lbs_inode = sizeof(struct inode_smack), |
| .lbs_ipc = sizeof(struct smack_known *), |
| .lbs_msg_msg = sizeof(struct smack_known *), |
| .lbs_superblock = sizeof(struct superblock_smack), |
| }; |
| |
| static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { |
| LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check), |
| LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), |
| LSM_HOOK_INIT(syslog, smack_syslog), |
| |
| LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup), |
| LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param), |
| |
| LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), |
| LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts), |
| LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts), |
| LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), |
| LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), |
| |
| LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec), |
| |
| LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security), |
| LSM_HOOK_INIT(inode_init_security, smack_inode_init_security), |
| LSM_HOOK_INIT(inode_link, smack_inode_link), |
| LSM_HOOK_INIT(inode_unlink, smack_inode_unlink), |
| LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir), |
| LSM_HOOK_INIT(inode_rename, smack_inode_rename), |
| LSM_HOOK_INIT(inode_permission, smack_inode_permission), |
| LSM_HOOK_INIT(inode_setattr, smack_inode_setattr), |
| LSM_HOOK_INIT(inode_getattr, smack_inode_getattr), |
| LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr), |
| LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr), |
| LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr), |
| LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr), |
| LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity), |
| LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity), |
| LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity), |
| LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid), |
| |
| LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security), |
| LSM_HOOK_INIT(file_ioctl, smack_file_ioctl), |
| LSM_HOOK_INIT(file_lock, smack_file_lock), |
| LSM_HOOK_INIT(file_fcntl, smack_file_fcntl), |
| LSM_HOOK_INIT(mmap_file, smack_mmap_file), |
| LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), |
| LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner), |
| LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask), |
| LSM_HOOK_INIT(file_receive, smack_file_receive), |
| |
| LSM_HOOK_INIT(file_open, smack_file_open), |
| |
| LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank), |
| LSM_HOOK_INIT(cred_free, smack_cred_free), |
| LSM_HOOK_INIT(cred_prepare, smack_cred_prepare), |
| LSM_HOOK_INIT(cred_transfer, smack_cred_transfer), |
| LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid), |
| LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as), |
| LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as), |
| LSM_HOOK_INIT(task_setpgid, smack_task_setpgid), |
| LSM_HOOK_INIT(task_getpgid, smack_task_getpgid), |
| LSM_HOOK_INIT(task_getsid, smack_task_getsid), |
| LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj), |
| LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj), |
| LSM_HOOK_INIT(task_setnice, smack_task_setnice), |
| LSM_HOOK_INIT(task_setioprio, smack_task_setioprio), |
| LSM_HOOK_INIT(task_getioprio, smack_task_getioprio), |
| LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler), |
| LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler), |
| LSM_HOOK_INIT(task_movememory, smack_task_movememory), |
| LSM_HOOK_INIT(task_kill, smack_task_kill), |
| LSM_HOOK_INIT(task_to_inode, smack_task_to_inode), |
| |
| LSM_HOOK_INIT(ipc_permission, smack_ipc_permission), |
| LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid), |
| |
| LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security), |
| |
| LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security), |
| LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate), |
| LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl), |
| LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd), |
| LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv), |
| |
| LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security), |
| LSM_HOOK_INIT(shm_associate, smack_shm_associate), |
| LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl), |
| LSM_HOOK_INIT(shm_shmat, smack_shm_shmat), |
| |
| LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security), |
| LSM_HOOK_INIT(sem_associate, smack_sem_associate), |
| LSM_HOOK_INIT(sem_semctl, smack_sem_semctl), |
| LSM_HOOK_INIT(sem_semop, smack_sem_semop), |
| |
| LSM_HOOK_INIT(d_instantiate, smack_d_instantiate), |
| |
| LSM_HOOK_INIT(getprocattr, smack_getprocattr), |
| LSM_HOOK_INIT(setprocattr, smack_setprocattr), |
| |
| LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect), |
| LSM_HOOK_INIT(unix_may_send, smack_unix_may_send), |
| |
| LSM_HOOK_INIT(socket_post_create, smack_socket_post_create), |
| LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair), |
| #ifdef SMACK_IPV6_PORT_LABELING |
| LSM_HOOK_INIT(socket_bind, smack_socket_bind), |
| #endif |
| LSM_HOOK_INIT(socket_connect, smack_socket_connect), |
| LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg), |
| LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb), |
| LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream), |
| LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram), |
| LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security), |
| LSM_HOOK_INIT(sk_free_security, smack_sk_free_security), |
| LSM_HOOK_INIT(sock_graft, smack_sock_graft), |
| LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request), |
| LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone), |
| |
| /* key management security hooks */ |
| #ifdef CONFIG_KEYS |
| LSM_HOOK_INIT(key_alloc, smack_key_alloc), |
| LSM_HOOK_INIT(key_free, smack_key_free), |
| LSM_HOOK_INIT(key_permission, smack_key_permission), |
| LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity), |
| #ifdef CONFIG_KEY_NOTIFICATIONS |
| LSM_HOOK_INIT(watch_key, smack_watch_key), |
| #endif |
| #endif /* CONFIG_KEYS */ |
| |
| #ifdef CONFIG_WATCH_QUEUE |
| LSM_HOOK_INIT(post_notification, smack_post_notification), |
| #endif |
| |
| /* Audit hooks */ |
| #ifdef CONFIG_AUDIT |
| LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init), |
| LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known), |
| LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match), |
| #endif /* CONFIG_AUDIT */ |
| |
| LSM_HOOK_INIT(ismaclabel, smack_ismaclabel), |
| LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx), |
| LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid), |
| LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx), |
| LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx), |
| LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx), |
| LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up), |
| LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr), |
| LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as), |
| #ifdef CONFIG_IO_URING |
| LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds), |
| LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll), |
| LSM_HOOK_INIT(uring_cmd, smack_uring_cmd), |
| #endif |
| }; |
| |
| |
| static __init void init_smack_known_list(void) |
| { |
| /* |
| * Initialize rule list locks |
| */ |
| mutex_init(&smack_known_huh.smk_rules_lock); |
| mutex_init(&smack_known_hat.smk_rules_lock); |
| mutex_init(&smack_known_floor.smk_rules_lock); |
| mutex_init(&smack_known_star.smk_rules_lock); |
| mutex_init(&smack_known_web.smk_rules_lock); |
| /* |
| * Initialize rule lists |
| */ |
| INIT_LIST_HEAD(&smack_known_huh.smk_rules); |
| INIT_LIST_HEAD(&smack_known_hat.smk_rules); |
| INIT_LIST_HEAD(&smack_known_star.smk_rules); |
| INIT_LIST_HEAD(&smack_known_floor.smk_rules); |
| INIT_LIST_HEAD(&smack_known_web.smk_rules); |
| /* |
| * Create the known labels list |
| */ |
| smk_insert_entry(&smack_known_huh); |
| smk_insert_entry(&smack_known_hat); |
| smk_insert_entry(&smack_known_star); |
| smk_insert_entry(&smack_known_floor); |
| smk_insert_entry(&smack_known_web); |
| } |
| |
| /** |
| * smack_init - initialize the smack system |
| * |
| * Returns 0 on success, -ENOMEM is there's no memory |
| */ |
| static __init int smack_init(void) |
| { |
| struct cred *cred = (struct cred *) current->cred; |
| struct task_smack *tsp; |
| |
| smack_rule_cache = KMEM_CACHE(smack_rule, 0); |
| if (!smack_rule_cache) |
| return -ENOMEM; |
| |
| /* |
| * Set the security state for the initial task. |
| */ |
| tsp = smack_cred(cred); |
| init_task_smack(tsp, &smack_known_floor, &smack_known_floor); |
| |
| /* |
| * Register with LSM |
| */ |
| security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); |
| smack_enabled = 1; |
| |
| pr_info("Smack: Initializing.\n"); |
| #ifdef CONFIG_SECURITY_SMACK_NETFILTER |
| pr_info("Smack: Netfilter enabled.\n"); |
| #endif |
| #ifdef SMACK_IPV6_PORT_LABELING |
| pr_info("Smack: IPv6 port labeling enabled.\n"); |
| #endif |
| #ifdef SMACK_IPV6_SECMARK_LABELING |
| pr_info("Smack: IPv6 Netfilter enabled.\n"); |
| #endif |
| |
| /* initialize the smack_known_list */ |
| init_smack_known_list(); |
| |
| return 0; |
| } |
| |
| /* |
| * Smack requires early initialization in order to label |
| * all processes and objects when they are created. |
| */ |
| DEFINE_LSM(smack) = { |
| .name = "smack", |
| .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, |
| .blobs = &smack_blob_sizes, |
| .init = smack_init, |
| }; |