From: David S. Miller <davem@redhat.com>
Date: Sat, 21 Jun 2008 01:15:34 -0400
Subject: [net] sctp: make sure sctp_addr does not overflow
Message-id: 20080621.011534.39478761.davem@redhat.com
O-Subject: [PATCH]: SCTP local root hole...
Bugzilla: 452483
RH-Acked-by: Alexander Viro <aviro@redhat.com>
RH-Acked-by: Neil Horman <nhorman@redhat.com>
RH-Acked-by: James Morris <jmorris@redhat.com>

It's not remotely exploitable but any local user can probably use this
to gain root or other arbitrary privileges as it allows writing over
kernel memory.

I just checked this into the net-2.6 tree and it will thus be upstream
in Linus's tree in the next day or two.  It will hopefully got to
-stable immediately afterwards.

--------------------

sctp: Make sure N * sizeof(union sctp_addr) does not overflow.

As noticed by Gabriel Campana, the kmalloc() length arg
passed in by sctp_getsockopt_local_addrs_old() can overflow
if ->addr_num is large enough.

Therefore, enforce an appropriate limit.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 9adc06f..cdddff5 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4024,7 +4024,9 @@ static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
 	if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs_old)))
 		return -EFAULT;
 
-	if (getaddrs.addr_num <= 0) return -EINVAL;
+	if (getaddrs.addr_num <= 0 ||
+	    getaddrs.addr_num >= (INT_MAX / sizeof(union sctp_addr)))
+		return -EINVAL;
 	/*
 	 *  For UDP-style sockets, id specifies the association to query.
 	 *  If the id field is set to the value '0' then the locally bound