udp: Fix rcv socket locking
[ Upstream commits d97106ea52aa57e63ff40d04479016836bbb5a4e and
93821778def10ec1e69aa3ac10adee975dad4ff3 ]
The previous patch in response to the recursive locking on IPsec
reception is broken as it tries to drop the BH socket lock while in
user context.
This patch fixes it by shrinking the section protected by the
socket lock to sock_queue_rcv_skb only. The only reason we added
the lock is for the accounting which happens in that function.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 9703c87..b924502 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -956,6 +956,27 @@
return 0;
}
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ int is_udplite = IS_UDPLITE(sk);
+ int rc;
+
+ if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
+ /* Note that an ENOMEM error is charged twice */
+ if (rc == -ENOMEM)
+ UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS,
+ is_udplite);
+ goto drop;
+ }
+
+ return 0;
+
+drop:
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
+ kfree_skb(skb);
+ return -1;
+}
+
/* returns:
* -1: error
* 0: success
@@ -1046,14 +1067,16 @@
goto drop;
}
- if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
- /* Note that an ENOMEM error is charged twice */
- if (rc == -ENOMEM)
- UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, is_udplite);
- goto drop;
- }
+ rc = 0;
- return 0;
+ bh_lock_sock(sk);
+ if (!sock_owned_by_user(sk))
+ rc = __udp_queue_rcv_skb(sk, skb);
+ else
+ sk_add_backlog(sk, skb);
+ bh_unlock_sock(sk);
+
+ return rc;
drop:
UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
@@ -1091,15 +1114,7 @@
skb1 = skb_clone(skb, GFP_ATOMIC);
if (skb1) {
- int ret = 0;
-
- bh_lock_sock_nested(sk);
- if (!sock_owned_by_user(sk))
- ret = udp_queue_rcv_skb(sk, skb1);
- else
- sk_add_backlog(sk, skb1);
- bh_unlock_sock(sk);
-
+ int ret = udp_queue_rcv_skb(sk, skb1);
if (ret > 0)
/* we should probably re-process instead
* of dropping packets here. */
@@ -1192,13 +1207,7 @@
uh->dest, inet_iif(skb), udptable);
if (sk != NULL) {
- int ret = 0;
- bh_lock_sock_nested(sk);
- if (!sock_owned_by_user(sk))
- ret = udp_queue_rcv_skb(sk, skb);
- else
- sk_add_backlog(sk, skb);
- bh_unlock_sock(sk);
+ int ret = udp_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
@@ -1493,7 +1502,7 @@
.sendmsg = udp_sendmsg,
.recvmsg = udp_recvmsg,
.sendpage = udp_sendpage,
- .backlog_rcv = udp_queue_rcv_skb,
+ .backlog_rcv = __udp_queue_rcv_skb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v4_get_port,
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 53739de..4e36c57 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -373,7 +373,7 @@
uh->source, saddr, dif))) {
struct sk_buff *buff = skb_clone(skb, GFP_ATOMIC);
if (buff) {
- bh_lock_sock_nested(sk2);
+ bh_lock_sock(sk2);
if (!sock_owned_by_user(sk2))
udpv6_queue_rcv_skb(sk2, buff);
else
@@ -381,7 +381,7 @@
bh_unlock_sock(sk2);
}
}
- bh_lock_sock_nested(sk);
+ bh_lock_sock(sk);
if (!sock_owned_by_user(sk))
udpv6_queue_rcv_skb(sk, skb);
else
@@ -499,7 +499,7 @@
/* deliver */
- bh_lock_sock_nested(sk);
+ bh_lock_sock(sk);
if (!sock_owned_by_user(sk))
udpv6_queue_rcv_skb(sk, skb);
else
