| From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 133/136] phonet: properly unshare skbs in phonet_rcv() | Date | Tue, 2 Feb 2016 10:15:28 -0800 |
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3.13.11-ckt34 -stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 7aaed57c5c2890634cfadf725173c7c68ea4cb4f ]
Ivaylo Dimitrov reported a regression caused by commit 7866a621043f ("dev: add per net_device packet type chains").
skb->dev becomes NULL and we crash in __netif_receive_skb_core().
Before above commit, different kind of bugs or corruptions could happen without major crash.
But the root cause is that phonet_rcv() can queue skb without checking if skb is shared or not.
Many thanks to Ivaylo Dimitrov for his help, diagnosis and tests.
Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Remi Denis-Courmont <courmisch@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/phonet/af_phonet.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c index 5a940db..f022922 100644 --- a/net/phonet/af_phonet.c +++ b/net/phonet/af_phonet.c @@ -377,6 +377,10 @@ static int phonet_rcv(struct sk_buff *skb, struct net_device *dev, struct sockaddr_pn sa; u16 len; + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + return NET_RX_DROP; + /* check we have at least a full Phonet header */ if (!pskb_pull(skb, sizeof(struct phonethdr))) goto out; -- 1.9.1
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