From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF1B2C43441 for ; Wed, 28 Nov 2018 09:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CEF62081C for ; Wed, 28 Nov 2018 09:21:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="FWEMTPvj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9CEF62081C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=163.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728083AbeK1UWC (ORCPT ); Wed, 28 Nov 2018 15:22:02 -0500 Received: from m12-14.163.com ([220.181.12.14]:47214 "EHLO m12-14.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727616AbeK1UWB (ORCPT ); Wed, 28 Nov 2018 15:22:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=CbfxdGke0HEMBGu+So pRdrIaYtU/j5g7rmGw+u6eV8c=; b=FWEMTPvj27bgJYepzGR7cao/na0jLP8Q+8 NaQrbg+eWeZoBchJE0gzdHje85sQgXmvYFuN8vnmHwc8LjM5tGJ2UzUMTt7T4Ulv 62KKMrmfl2+89vVy6JkK1lwIypHmD/aG4ndtNN3AjPB8SKgLi8yjwVRmhtLoAKCj UCrLDBRnI= Received: from bp.localdomain (unknown [106.120.213.96]) by smtp10 (Coremail) with SMTP id DsCowAD3W8j0Xf5bV1xACQ--.53578S3; Wed, 28 Nov 2018 17:20:54 +0800 (CST) From: Pan Bian To: Jose Abreu , "David S. Miller" Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH] net: dwc-xlgmac: set skb to NULL after freeing it Date: Wed, 28 Nov 2018 17:20:53 +0800 Message-Id: <1543396853-35188-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: DsCowAD3W8j0Xf5bV1xACQ--.53578S3 X-Coremail-Antispam: 1Uf129KBjvJXoW7Cw1DKw1rJF4fWr13Xry5Jwb_yoW8Jw15pa yUJ3yUXrn3Jr42qaykXw4rZF15Gan8JFZ5Gr9rCw13X3ZIyr1a9r1qqa4YyFWUCFZ3uaya qw4Y9rn7WFn8XFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07j1Ap5UUUUU= X-Originating-IP: [106.120.213.96] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/1tbiQAMNclSIYVNlRgAAsx Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The buffer skb is freed via dev_kfree_skb in a loop. After freeing skb, the value of packet_count is updated via packet_count++. If packet_count happens to equal the upper bound (i.e., budget), the loop will be broken and skb may be assigned to desc_data->state.skb. Resulting that desc_data->state.skb may point to a freed memory chunk. To fix this, the patch sets skb to NULL after dev_kfree_skb(skb). Signed-off-by: Pan Bian --- drivers/net/ethernet/synopsys/dwc-xlgmac-net.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/synopsys/dwc-xlgmac-net.c b/drivers/net/ethernet/synopsys/dwc-xlgmac-net.c index 1f8e960..a0d28c4 100644 --- a/drivers/net/ethernet/synopsys/dwc-xlgmac-net.c +++ b/drivers/net/ethernet/synopsys/dwc-xlgmac-net.c @@ -1180,6 +1180,7 @@ static int xlgmac_rx_poll(struct xlgmac_channel *channel, int budget) netif_err(pdata, rx_err, netdev, "error in received packet\n"); dev_kfree_skb(skb); + skb = NULL; goto next_packet; } @@ -1227,6 +1228,7 @@ static int xlgmac_rx_poll(struct xlgmac_channel *channel, int budget) netif_err(pdata, rx_err, netdev, "packet length exceeds configured MTU\n"); dev_kfree_skb(skb); + skb = NULL; goto next_packet; } -- 2.7.4