commit 93a35f59f1b13a02674877e3efdf07ae47e34052
author Eric Dumazet <edumazet@google.com> Thu Oct 23 06:30:30 2014 -0700
committer David S. Miller <davem@davemloft.net> Sun Oct 26 22:47:23 2014 -0400
tree c05bc7c401ea7889059f9c15e4c28807c38b0105
parent aa9c5579153535fb317a9d34c7d8eaf02b7ef4cd

net: napi_reuse_skb() should check pfmemalloc

Do not reuse skb if it was pfmemalloc tainted, otherwise
future frame might be dropped anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Roman Gushchin <klamm@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

diff --git a/net/core/dev.c b/net/core/dev.c
index b793e35..945bbd0 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4157,6 +4157,10 @@
 
 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
 {
+	if (unlikely(skb->pfmemalloc)) {
+		consume_skb(skb);
+		return;
+	}
 	__skb_pull(skb, skb_headlen(skb));
 	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));