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 <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/atm/svc.c b/net/atm/svc.c
index de1e4f2..8fb54dc 100644
--- a/net/atm/svc.c
+++ b/net/atm/svc.c
@@ -293,7 +293,10 @@
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 @@
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: