From: Vasiliy Kulikov <segoon@openwall.com>
Date: Mon, 6 Aug 2012 03:55:29 +0000 (+0000)
Subject: ip: fix error handling in ip_finish_output2()
X-Git-Tag: firefly_0821_release~3680^2~2237^2~3
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9871f1ad677d95ffeca80e2c21b70af9bfc9cc91;p=firefly-linux-kernel-4.4.55.git

ip: fix error handling in ip_finish_output2()

__neigh_create() returns either a pointer to struct neighbour or PTR_ERR().
But the caller expects it to return either a pointer or NULL.  Replace
the NULL check with IS_ERR() check.

The bug was introduced in a263b3093641fb1ec377582c90986a7fd0625184
("ipv4: Make neigh lookups directly in output packet path.").

Signed-off-by: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index ba39a52d18c1..76dde25fb9a0 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -197,7 +197,7 @@ static inline int ip_finish_output2(struct sk_buff *skb)
 	neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
 	if (unlikely(!neigh))
 		neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);
-	if (neigh) {
+	if (!IS_ERR(neigh)) {
 		int res = dst_neigh_output(dst, neigh, skb);
 
 		rcu_read_unlock_bh();