From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755548AbcA2B3H (ORCPT ); Thu, 28 Jan 2016 20:29:07 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:33623 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755436AbcA2BYT (ORCPT ); Thu, 28 Jan 2016 20:24:19 -0500 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , Remi Denis-Courmont , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 194/210] phonet: properly unshare skbs in phonet_rcv() Date: Thu, 28 Jan 2016 17:18:52 -0800 Message-Id: <1454030348-17736-195-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1454030348-17736-1-git-send-email-kamal@canonical.com> References: <1454030348-17736-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt14 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Eric Dumazet [ 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 Tested-by: Ivaylo Dimitrov Signed-off-by: Eric Dumazet Cc: Remi Denis-Courmont Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- 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 32ab87d..11d0b29 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