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authorEric Dumazet <edumazet@google.com>2012-10-22 09:03:40 +0000
committerDavid S. Miller <davem@davemloft.net>2012-10-22 15:16:07 -0400
commit3d861f661006606bf159fd6bd973e83dbf21d0f9 (patch)
tree6f141e16d0d0160b515271cee5fdb896599c133c /net
parent8a6e29d6d037de0dd62fe6648ba9b29866db5416 (diff)
downloadlinux-3d861f661006606bf159fd6bd973e83dbf21d0f9.tar.gz
net: fix secpath kmemleak
Mike Kazantsev found 3.5 kernels and beyond were leaking memory,
and tracked the faulty commit to a1c7fff7e18f59e ("net:
netdev_alloc_skb() use build_skb()")

While this commit seems fine, it uncovered a bug introduced
in commit bad43ca8325 ("net: introduce skb_try_coalesce()), in function
kfree_skb_partial()"):

If head is stolen, we free the sk_buff,
without removing references on secpath (skb->sp).

So IPsec + IP defrag/reassembly (using skb coalescing), or
TCP coalescing could leak secpath objects.

Fix this bug by calling skb_release_head_state(skb) to properly
release all possible references to linked objects.

Reported-by: Mike Kazantsev <mk.fraggod@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Bisected-by: Mike Kazantsev <mk.fraggod@gmail.com>
Tested-by: Mike Kazantsev <mk.fraggod@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/skbuff.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6e04b1fa11f2..4007c1437fda 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3379,10 +3379,12 @@ EXPORT_SYMBOL(__skb_warn_lro_forwarding);
 
 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen)
 {
-	if (head_stolen)
+	if (head_stolen) {
+		skb_release_head_state(skb);
 		kmem_cache_free(skbuff_head_cache, skb);
-	else
+	} else {
 		__kfree_skb(skb);
+	}
 }
 EXPORT_SYMBOL(kfree_skb_partial);