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| author | Arjan van de Ven <arjan@linux.intel.com> | 2009-09-26 20:51:14 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-09-28 16:55:06 -0400 |
| commit | 8503bd8c7dc6f82ec2de9d05e0a476e6ca5adc8b (patch) | |
| tree | 42da5de2f0ee624e675d7b27f7e8c05301de0d2d | |
| parent | 0ff716136ab73d2fc1edc0664e38169e7a76bb9a (diff) | |
| download | linux-3.10-8503bd8c7dc6f82ec2de9d05e0a476e6ca5adc8b.tar.gz linux-3.10-8503bd8c7dc6f82ec2de9d05e0a476e6ca5adc8b.tar.bz2 linux-3.10-8503bd8c7dc6f82ec2de9d05e0a476e6ca5adc8b.zip | |
wext: Add bound checks for copy_from_user
The wireless extensions have a copy_from_user to a local stack
array "essid", but both me and gcc have failed to find where
the bounds for this copy are located in the code.
This patch adds some basic sanity checks for the copy length
to make sure that we don't overflow the stack buffer.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | net/wireless/wext.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/net/wireless/wext.c b/net/wireless/wext.c index 5b4a0cee441..ac4ac26b53c 100644 --- a/net/wireless/wext.c +++ b/net/wireless/wext.c @@ -773,10 +773,13 @@ static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd, essid_compat = 1; else if (IW_IS_SET(cmd) && (iwp->length != 0)) { char essid[IW_ESSID_MAX_SIZE + 1]; + unsigned int len; + len = iwp->length * descr->token_size; - err = copy_from_user(essid, iwp->pointer, - iwp->length * - descr->token_size); + if (len > IW_ESSID_MAX_SIZE) + return -EFAULT; + + err = copy_from_user(essid, iwp->pointer, len); if (err) return -EFAULT; |