Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753419AbcDVLcY (ORCPT ); Fri, 22 Apr 2016 07:32:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:43987 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753217AbcDVLGN (ORCPT ); Fri, 22 Apr 2016 07:06:13 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Sergei Shtylyov , "David S . Miller" , Jiri Slaby Subject: [PATCH 3.12 24/78] sh_eth: fix NULL pointer dereference in sh_eth_ring_format() Date: Fri, 22 Apr 2016 13:05:07 +0200 Message-Id: X-Mailer: git-send-email 2.8.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1308 Lines: 36 From: Sergei Shtylyov 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ Upstream commit c1b7fca65070bfadca94dd53a4e6b71cd4f69715 ] In a low memory situation, if netdev_alloc_skb() fails on a first RX ring loop iteration in sh_eth_ring_format(), 'rxdesc' is still NULL. Avoid kernel oops by adding the 'rxdesc' check after the loop. Reported-by: Wolfram Sang Signed-off-by: Sergei Shtylyov Signed-off-by: David S. Miller Signed-off-by: Jiri Slaby --- drivers/net/ethernet/renesas/sh_eth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index bee6e49c5542..d4ecb2fff4e4 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1069,7 +1069,8 @@ static void sh_eth_ring_format(struct net_device *ndev) mdp->dirty_rx = (u32) (i - mdp->num_rx_ring); /* Mark the last entry as wrapping the ring. */ - rxdesc->status |= cpu_to_edmac(mdp, RD_RDEL); + if (rxdesc) + rxdesc->status |= cpu_to_edmac(mdp, RD_RDEL); memset(mdp->tx_ring, 0, tx_ringsize); -- 2.8.1