From 17b24b3c97498935a2ef9777370b1151dfed3f6f Mon Sep 17 00:00:00 2001 From: Chas Williams Date: Thu, 4 Dec 2008 14:58:13 -0800 Subject: [PATCH] ATM: CVE-2008-5079: duplicate listen() on socket corrupts the vcc table As reported by Hugo Dias that it is possible to cause a local denial of service attack by calling the svc_listen function twice on the same socket and reading /proc/net/atm/*vc Signed-off-by: Chas Williams Signed-off-by: David S. Miller --- net/atm/svc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/atm/svc.c b/net/atm/svc.c index de1e4f2f3a4..8fb54dc870b 100644 --- a/net/atm/svc.c +++ b/net/atm/svc.c @@ -293,7 +293,10 @@ static int svc_listen(struct socket *sock,int backlog) error = -EINVAL; goto out; } - vcc_insert_socket(sk); + if (test_bit(ATM_VF_LISTEN, &vcc->flags)) { + error = -EADDRINUSE; + goto out; + } set_bit(ATM_VF_WAITING, &vcc->flags); prepare_to_wait(sk->sk_sleep, &wait, TASK_UNINTERRUPTIBLE); sigd_enq(vcc,as_listen,NULL,NULL,&vcc->local); @@ -307,6 +310,7 @@ static int svc_listen(struct socket *sock,int backlog) goto out; } set_bit(ATM_VF_LISTEN,&vcc->flags); + vcc_insert_socket(sk); sk->sk_max_ack_backlog = backlog > 0 ? backlog : ATM_BACKLOG_DEFAULT; error = -sk->sk_err; out: -- 2.41.1