Messages in this thread Patch in this message | | | Date | Sun, 23 Oct 2011 08:24:52 +0200 | From | Greg KH <> | Subject | [24/27] x25: Prevent skb overreads when checking call user data |
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3.0-stable review patch. If anyone has any objections, please let us know.
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From: Matthew Daley <mattjd@gmail.com>
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: Greg Kroah-Hartman <gregkh@suse.de>
--- net/x25/af_x25.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -295,7 +295,8 @@ static struct sock *x25_find_listener(st * 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) {
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