| From | Paul Gortmaker <> | Subject | [v2.6.34-stable 062/165] x25: Prevent skb overreads when checking call user data | Date | Wed, 15 Aug 2012 15:46:46 -0400 |
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From: Matthew Daley <mattjd@gmail.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
commit 7f81e25befdfb3272345a2e775f520e1d515fa20 upstream.
x25_find_listener does not check that the amount of call user data given in the skb is big enough in per-socket comparisons, hence buffer overreads may occur. Fix this by adding a check.
Signed-off-by: Matthew Daley <mattjd@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Andrew Hendry <andrew.hendry@gmail.com> Acked-by: Andrew Hendry <andrew.hendry@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- net/x25/af_x25.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 36e84e1..3117b9e 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -296,7 +296,8 @@ static struct sock *x25_find_listener(struct x25_address *addr, * Found a listening socket, now check the incoming * call user data vs this sockets call user data */ - if(skb->len > 0 && x25_sk(s)->cudmatchlength > 0) { + if (x25_sk(s)->cudmatchlength > 0 && + skb->len >= x25_sk(s)->cudmatchlength) { if((memcmp(x25_sk(s)->calluserdata.cuddata, skb->data, x25_sk(s)->cudmatchlength)) == 0) { -- 1.7.12.rc2
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