[PATCH 1/1] af-packet: fix oops when socket is not present

[Eric Leblond <eric@regit.org>]

When skb->sk is NULL and when packet fanout is used, there is a
crash in match_fanout_group where skb->sk is accessed.
This patch fixes the issue by returning false as soon as the
socket is NULL: this correspond to the wanted behavior because
the kernel as to resend the skb to all the listening socket in
this case.

Signed-off-by: Eric Leblond <eric@regit.org>
---
 net/core/dev.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index b4978e2..c7b5293 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1666,7 +1666,7 @@ static inline int deliver_skb(struct sk_buff *skb,
 
 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
 {
-	if (ptype->af_packet_priv == NULL)
+	if ((ptype->af_packet_priv == NULL) || (skb->sk == NULL))
 		return false;
 
 	if (ptype->id_match)
-- 
1.7.10.4