From patchwork Mon Jan 11 13:42:54 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 8003841 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: X-Original-To: patchwork-linux-wireless@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 688E1BEEE5 for ; Mon, 11 Jan 2016 13:43:00 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8B32420279 for ; Mon, 11 Jan 2016 13:42:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9EE620220 for ; Mon, 11 Jan 2016 13:42:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932367AbcAKNmx (ORCPT ); Mon, 11 Jan 2016 08:42:53 -0500 Received: from m12-12.163.com ([220.181.12.12]:48182 "EHLO m12-12.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758042AbcAKNmw (ORCPT ); Mon, 11 Jan 2016 08:42:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=8MhzmIA1uGrtLo8X2r hnX0pU+zv8C3nm2xao24te/SY=; b=e+5/bxKSLazRj/PXD9qTtIeH0QfT9fBAts 0gYvqULGybRBPL+xTDYkksa7Ocsiaag4hSvklK63ilArZwBngY8uGzAYQKN5AGhI n2pn9XTysxf3AY8m7yyeGb6f1WmB1Ld1WBvpYA33pq1vuNU0U2iHc9WjjJF//Rv6 5HRHQq+Tg= Received: from bai-oslab.tsinghua.edu.cn (unknown [166.111.70.58]) by smtp8 (Coremail) with SMTP id DMCowEBZ9E9HsZNWJzIRAA--.188S2; Mon, 11 Jan 2016 21:42:35 +0800 (CST) From: Jia-Ju Bai To: sgruszka@redhat.com, kvalo@codeaurora.org, johannes.berg@intel.com, emmanuel.grumbach@intel.com Cc: ilw@linux.intel.com, linuxwifi@intel.com, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, Jia-Ju Bai Subject: [PATCH v2] iwl4965: Fix a null pointer dereference in il_tx_queue_free and il_cmd_queue_free Date: Mon, 11 Jan 2016 21:42:54 +0800 Message-Id: <1452519775-7049-1-git-send-email-baijiaju1990@163.com> X-Mailer: git-send-email 1.7.9.5 X-CM-TRANSID: DMCowEBZ9E9HsZNWJzIRAA--.188S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7CryUWFyUuF4fCF18Xw1DKFg_yoW8Cw4UpF W3Cr90kw4DXF42q39FyF4rZay5Xan5Jr4UWayruws8Aw1fCFySvF1jkF1I9rWkZFsF9a4F vrWq9F1rWF4DJ37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UENtsUUUUU= X-Originating-IP: [166.111.70.58] X-CM-SenderInfo: xedlyx5dmximizq6il2tof0z/xtbBRQ7selO-zkw+KgAAsn Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, FREEMAIL_FROM,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If "txq->cmd = kzalloc(...)" in il_tx_queue_init fails, "kfree(txq->cmd[i])" in il_tx_queue_free and il_cmd_queue_free in iwl4965_hw_txq_ctx_free will causes a null pointer dereference, because txq->cmd is NULL at that time. This patch fixes this problem by adding a if-check before kfree. To avoid double free in il_tx_queue_free and il_cmd_queue_free caused by the fixing, txq->meta and txq->cmd in error handling code of il_tx_queue_init are assigned null values. Otherwise, a double free will occur. This patch has been tested in real device, and it actually fixes the bug. Thanks Stanislaw for his suggestion. Signed-off-by: Jia-Ju Bai Acked-by: Stanislaw Gruszka --- drivers/net/wireless/iwlegacy/common.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/iwlegacy/common.c b/drivers/net/wireless/iwlegacy/common.c index 8871145..092ecbc 100644 --- a/drivers/net/wireless/iwlegacy/common.c +++ b/drivers/net/wireless/iwlegacy/common.c @@ -2794,8 +2794,10 @@ il_tx_queue_free(struct il_priv *il, int txq_id) il_tx_queue_unmap(il, txq_id); /* De-alloc array of command/tx buffers */ - for (i = 0; i < TFD_TX_CMD_SLOTS; i++) - kfree(txq->cmd[i]); + if (txq->cmd) { + for (i = 0; i < TFD_TX_CMD_SLOTS; i++) + kfree(txq->cmd[i]); + } /* De-alloc circular buffer of TFDs */ if (txq->q.n_bd) @@ -2873,8 +2875,10 @@ il_cmd_queue_free(struct il_priv *il) il_cmd_queue_unmap(il); /* De-alloc array of command/tx buffers */ - for (i = 0; i <= TFD_CMD_SLOTS; i++) - kfree(txq->cmd[i]); + if (txq->cmd) { + for (i = 0; i <= TFD_CMD_SLOTS; i++) + kfree(txq->cmd[i]); + } /* De-alloc circular buffer of TFDs */ if (txq->q.n_bd) @@ -3080,7 +3084,9 @@ err: kfree(txq->cmd[i]); out_free_arrays: kfree(txq->meta); + txq->meta = NULL; kfree(txq->cmd); + txq->cmd = NULL; return -ENOMEM; }