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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 620FAC433FE for ; Thu, 14 Apr 2022 05:31:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239875AbiDNFeM (ORCPT ); Thu, 14 Apr 2022 01:34:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43988 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239861AbiDNFeK (ORCPT ); Thu, 14 Apr 2022 01:34:10 -0400 Received: from zju.edu.cn (mail.zju.edu.cn [61.164.42.155]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7E5273B54F; Wed, 13 Apr 2022 22:31:42 -0700 (PDT) Received: from ubuntu.localdomain (unknown [10.15.192.164]) by mail-app4 (Coremail) with SMTP id cS_KCgDHr_KqsVdi+oM1AQ--.59165S4; Thu, 14 Apr 2022 13:31:35 +0800 (CST) From: Duoming Zhou To: krzk@kernel.org, linux-kernel@vger.kernel.org Cc: davem@davemloft.net, gregkh@linuxfoundation.org, alexander.deucher@amd.com, akpm@linux-foundation.org, broonie@kernel.org, netdev@vger.kernel.org, linma@zju.edu.cn, Duoming Zhou Subject: [PATCH V2 2/3] drivers: nfc: nfcmrvl: fix double free bug in nfc_fw_download_done() Date: Thu, 14 Apr 2022 13:31:21 +0800 Message-Id: <538873335b034d7d97a08d2343e898cfa924918a.1649913521.git.duoming@zju.edu.cn> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-CM-TRANSID: cS_KCgDHr_KqsVdi+oM1AQ--.59165S4 X-Coremail-Antispam: 1UD129KBjvJXoW7Cw1DZFW8KF4ktF15tr43Jrb_yoW8ZFW5pr WrGFy2yr4DAr4jvFWrtFyDWrs8Cw47CryUGFZrG3yfZFn8tFyqyr1kGFyrZF4DWr48ta15 K39xJayjkanYvr7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvm1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJr0_GcWl84ACjcxK6I8E 87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c 8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_ Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwI xGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IY c2Ij64vIr41l42xK82IY6x8ErcxFaVAv8VW8uw4UJr1UMxC20s026xCaFVCjc4AY6r1j6r 4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF 67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2I x0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2 z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnU UI43ZEXa7VUbXdbUUUUUU== X-CM-SenderInfo: qssqjiasttq6lmxovvfxof0/1tbiAgITAVZdtZLd3gAgsd Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are potential double free bug in nfc_fw_download_done(). The timer handler fw_dnld_timeout() and work item fw_dnld_rx_work() could both reach in fw_dnld_over() and nfc_fw_download_done() is not protected by any lock, which leads to double free. The race between fw_dnld_rx_work() and fw_dnld_timeout() can be shown as below: (Thread 1) | (Thread 2) fw_dnld_timeout | fw_dnld_rx_work | fw_dnld_over fw_dnld_over | nfc_fw_download_done nfc_fw_download_done | nfc_genl_fw_download_done nfc_genl_fw_download_done| nlmsg_free(msg) //(1) nlmsg_free(msg) //(2) | ... ... | The nlmsg_free() will deallocate sk_buff in position (1), but nlmsg_free will be deallocated again in position (2), which leads to double free. This patch adds spin_lock_irq() and check in fw_dnld_over() in order to synchronize among different threads that call fw_dnld_over(). So the double free bug could be prevented. Fixes: 3194c6870158e3 ("NFC: nfcmrvl: add firmware download support") Signed-off-by: Duoming Zhou Reviewed-by: Lin Ma --- Changes in V2: - Fix the check in spin_lock_irq. drivers/nfc/nfcmrvl/fw_dnld.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/nfc/nfcmrvl/fw_dnld.c b/drivers/nfc/nfcmrvl/fw_dnld.c index c22a4556db5..bb9e7e2bdec 100644 --- a/drivers/nfc/nfcmrvl/fw_dnld.c +++ b/drivers/nfc/nfcmrvl/fw_dnld.c @@ -115,8 +115,10 @@ static void fw_dnld_over(struct nfcmrvl_private *priv, u32 error) /* failed, halt the chip to avoid power consumption */ nfcmrvl_chip_halt(priv); } - - nfc_fw_download_done(priv->ndev->nfc_dev, priv->fw_dnld.name, error); + spin_lock_irq(&priv->fw_dnld.lock); + if (priv->ndev->nfc_dev->fw_download_in_progress) + nfc_fw_download_done(priv->ndev->nfc_dev, priv->fw_dnld.name, error); + spin_unlock_irq(&priv->fw_dnld.lock); } static void fw_dnld_timeout(struct timer_list *t) -- 2.17.1