From patchwork Mon Nov 26 16:55:08 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [018/270] net: fix secpath kmemleak Date: Mon, 26 Nov 2012 06:55:08 -0000 From: Herton Ronaldo Krzesinski X-Patchwork-Id: 201751 Message-Id: <1353949160-26803-19-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , "David S. Miller" 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 3d861f661006606bf159fd6bd973e83dbf21d0f9 upstream. 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 Signed-off-by: Eric Dumazet Bisected-by: Mike Kazantsev Tested-by: Mike Kazantsev Signed-off-by: David S. Miller Signed-off-by: Herton Ronaldo Krzesinski --- net/core/skbuff.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d124306..015f3a7 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3350,10 +3350,12 @@ 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);