From bc6e019b6ee65ff4ebf3ca272f774cf6c67db669 Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Thu, 3 Jan 2019 21:43:34 +0100 Subject: fou: Prevent unbounded recursion in GUE error handler also with UDP-Lite In commit 11789039da53 ("fou: Prevent unbounded recursion in GUE error handler"), I didn't take care of the case where UDP-Lite is encapsulated into UDP or UDP-Lite with GUE. From a syzbot report about a possibly similar issue with GUE on IPv6, I just realised the same thing might happen with a UDP-Lite inner payload. Also skip exception handling for inner UDP-Lite protocol. Fixes: 11789039da53 ("fou: Prevent unbounded recursion in GUE error handler") Signed-off-by: Stefano Brivio Signed-off-by: David S. Miller --- net/ipv4/fou.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c index 0c9f171fb085..632863541082 100644 --- a/net/ipv4/fou.c +++ b/net/ipv4/fou.c @@ -1065,7 +1065,8 @@ static int gue_err(struct sk_buff *skb, u32 info) * recursion. Besides, this kind of encapsulation can't even be * configured currently. Discard this. */ - if (guehdr->proto_ctype == IPPROTO_UDP) + if (guehdr->proto_ctype == IPPROTO_UDP || + guehdr->proto_ctype == IPPROTO_UDPLITE) return -EOPNOTSUPP; skb_set_transport_header(skb, -(int)sizeof(struct icmphdr)); -- cgit v1.2.3