From patchwork Wed Mar 2 15:26:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 591011 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 97F601402BC for ; Thu, 3 Mar 2016 02:26:31 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754846AbcCBP0Y (ORCPT ); Wed, 2 Mar 2016 10:26:24 -0500 Received: from sauhun.de ([89.238.76.85]:50158 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754309AbcCBP0W (ORCPT ); Wed, 2 Mar 2016 10:26:22 -0500 Received: from p5082e975.dip0.t-ipconnect.de ([80.130.233.117]:43996 helo=localhost) by pokefinder.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1ab8fI-0005s9-L7; Wed, 02 Mar 2016 16:26:16 +0100 From: Wolfram Sang To: netdev@vger.kernel.org Cc: Wolfram Sang , Simon Horman , Sergei Shtylyov , linux-renesas-soc@vger.kernel.org Subject: [PATCH] net: sh_eth: avoid NULL pointer dereference in ring setup Date: Wed, 2 Mar 2016 16:26:06 +0100 Message-Id: <1456932370-4143-1-git-send-email-wsa@the-dreams.de> X-Mailer: git-send-email 2.7.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Wolfram Sang When allocating an skb fails, rxdesc is still NULL (or the previous ring index on further iterations of the loop). However, this pointer is dereferenced after the loop. So, make sure rxdesc is updated immediately at the beginning of the loop. Reported-by: coverity (CID 1056464) Signed-off-by: Wolfram Sang Reported-by: Wolfram Sang --- drivers/net/ethernet/renesas/sh_eth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index a2767336b7c545..d5f13d54099734 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1120,6 +1120,7 @@ static void sh_eth_ring_format(struct net_device *ndev) /* build Rx ring buffer */ for (i = 0; i < mdp->num_rx_ring; i++) { + rxdesc = &mdp->rx_ring[i]; /* skb */ mdp->rx_skbuff[i] = NULL; skb = netdev_alloc_skb(ndev, skbuff_size); @@ -1128,7 +1129,6 @@ static void sh_eth_ring_format(struct net_device *ndev) sh_eth_set_receive_align(skb); /* RX descriptor */ - rxdesc = &mdp->rx_ring[i]; /* The size of the buffer is a multiple of 32 bytes. */ buf_len = ALIGN(mdp->rx_buf_sz, 32); rxdesc->len = cpu_to_le32(buf_len << 16);