From fb83ed496b9a654f60cd1d58a0e1e79ec5694808 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 10 Dec 2018 15:23:30 -0800 Subject: [PATCH] tipc: compare remote and local protocols in tipc_udp_enable() When TIPC_NLA_UDP_REMOTE is an IPv6 mcast address but TIPC_NLA_UDP_LOCAL is an IPv4 address, a NULL-ptr deref is triggered as the UDP tunnel sock is initialized to IPv4 or IPv6 sock merely based on the protocol in local address. We should just error out when the remote address and local address have different protocols. Reported-by: syzbot+eb4da3a20fad2e52555d@syzkaller.appspotmail.com Cc: Ying Xue Cc: Jon Maloy Signed-off-by: Cong Wang Acked-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/udp_media.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index 1b1ba1310ea7..4d85d71f16e2 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -679,6 +679,11 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b, if (err) goto err; + if (remote.proto != local.proto) { + err = -EINVAL; + goto err; + } + /* Checking remote ip address */ rmcast = tipc_udp_is_mcast_addr(&remote);