From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751815AbdITEqG (ORCPT ); Wed, 20 Sep 2017 00:46:06 -0400 Received: from omzsmtpe03.verizonbusiness.com ([199.249.25.208]:26488 "EHLO omzsmtpe03.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751626AbdITEp4 (ORCPT ); Wed, 20 Sep 2017 00:45:56 -0400 From: "Levin, Alexander (Sasha Levin)" Cc: Myungho Jung , "David S . Miller" , "Levin, Alexander (Sasha Levin)" X-Host: ranger.odc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH review for 4.4 31/47] net: core: Prevent from dereferencing null pointer when releasing SKB Thread-Topic: [PATCH review for 4.4 31/47] net: core: Prevent from dereferencing null pointer when releasing SKB Thread-Index: AQHTMcs7TDQXahqrSEWqMo41HTyR/w== Date: Wed, 20 Sep 2017 04:45:07 +0000 Message-ID: <20170920044445.7392-31-alexander.levin@verizon.com> References: <20170920044445.7392-1-alexander.levin@verizon.com> In-Reply-To: <20170920044445.7392-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v8K4u9V2025032 From: Myungho Jung [ Upstream commit 9899886d5e8ec5b343b1efe44f185a0e68dc6454 ] Added NULL check to make __dev_kfree_skb_irq consistent with kfree family of functions. Link: https://bugzilla.kernel.org/show_bug.cgi?id=195289 Signed-off-by: Myungho Jung Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 24d243084aab..dac52fa60f25 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2338,6 +2338,9 @@ void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason) { unsigned long flags; + if (unlikely(!skb)) + return; + if (likely(atomic_read(&skb->users) == 1)) { smp_rmb(); atomic_set(&skb->users, 0); -- 2.11.0