proc: proc_skip_spaces() shouldn't think it is working on C strings
commit bce9332220bd677d83b19d21502776ad555a0e73 upstream.
proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.
Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace). So use that as
inspiration, odd coding and all.
Now the calling convention actually makes sense and works for the
intended purpose.
Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index bbd0876..9890f93 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2041,13 +2041,14 @@
(char __user *)buffer, lenp, ppos);
}
-static size_t proc_skip_spaces(char **buf)
+static void proc_skip_spaces(char **buf, size_t *size)
{
- size_t ret;
- char *tmp = skip_spaces(*buf);
- ret = tmp - *buf;
- *buf = tmp;
- return ret;
+ while (*size) {
+ if (!isspace(**buf))
+ break;
+ (*size)--;
+ (*buf)++;
+ }
}
static void proc_skip_char(char **buf, size_t *size, const char v)
@@ -2260,7 +2261,7 @@
bool neg;
if (write) {
- left -= proc_skip_spaces(&p);
+ proc_skip_spaces(&p, &left);
if (!left)
break;
@@ -2291,7 +2292,7 @@
if (!write && !first && left && !err)
err = proc_put_char(&buffer, &left, '\n');
if (write && !err && left)
- left -= proc_skip_spaces(&p);
+ proc_skip_spaces(&p, &left);
if (write) {
kfree(kbuf);
if (first)
@@ -2543,7 +2544,7 @@
if (write) {
bool neg;
- left -= proc_skip_spaces(&p);
+ proc_skip_spaces(&p, &left);
if (!left)
break;
@@ -2576,7 +2577,7 @@
if (!write && !first && left && !err)
err = proc_put_char(&buffer, &left, '\n');
if (write && !err)
- left -= proc_skip_spaces(&p);
+ proc_skip_spaces(&p, &left);
if (write) {
kfree(kbuf);
if (first)
