| From | Greg Kroah-Hartman <> | Subject | [ 47/66] net: fix secpath kmemleak | Date | Wed, 14 Nov 2012 20:10:52 -0800 |
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3.6-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 3d861f661006606bf159fd6bd973e83dbf21d0f9 ]
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/core/skbuff.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3384,10 +3384,12 @@ 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);
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