diff options
| author | Linus Torvalds <torvalds@g5.osdl.org> | 2005-12-31 02:18:53 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-12-31 02:18:53 +0100 |
| commit | 8febdd85adaa41fa1fc1cb31286210fc2cd3ed0c (patch) | |
| tree | 2e1aaa5e4e68057a4e96a606e2ad0bcccedcd6df | |
| parent | Insanity avoidance in /proc (diff) | |
| download | linux-8febdd85adaa41fa1fc1cb31286210fc2cd3ed0c.tar.xz linux-8febdd85adaa41fa1fc1cb31286210fc2cd3ed0c.zip | |
sysctl: don't overflow the user-supplied buffer with '\0'
If the string was too long to fit in the user-supplied buffer,
the sysctl layer would zero-terminate it by writing past the
end of the buffer. Don't do that.
Noticed by Yi Yang <yang.y.yi@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | kernel/sysctl.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 9990e10192e8..ad0425a8f709 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2201,14 +2201,12 @@ int sysctl_string(ctl_table *table, int __user *name, int nlen, if (get_user(len, oldlenp)) return -EFAULT; if (len) { - l = strlen(table->data); + l = strlen(table->data)+1; if (len > l) len = l; if (len >= table->maxlen) len = table->maxlen; if(copy_to_user(oldval, table->data, len)) return -EFAULT; - if(put_user(0, ((char __user *) oldval) + len)) - return -EFAULT; if(put_user(len, oldlenp)) return -EFAULT; } |