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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 60DE1C11F86 for ; Tue, 6 Jul 2021 12:02:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49A45620DB for ; Tue, 6 Jul 2021 12:02:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237335AbhGFMEJ (ORCPT ); Tue, 6 Jul 2021 08:04:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:47556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237316AbhGFLgF (ORCPT ); Tue, 6 Jul 2021 07:36:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5A17B61EF7; Tue, 6 Jul 2021 11:26:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625570811; bh=MB9zlgkJnCKies2mtTgzKmFoPVEsNrYGrm3alODX5fQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uz9FEHsS1j7fYUcv7dZdkZhBOF2pWMzMPDEsfCeNaoCAOwLN6HPpdSqW97DFOGs+Q N9vAulFa2fkoDh7BjCP5sphnGsdl7hieZrMaqI1+Qo0t7f7ohcuKdTzWk39bRubMiQ rlh+jTYwVKgVR4kMvEH8m5V0XaLtwra8ZMX5RuSLWNggyFTIDJPpLi49zo9tdmVguX QJ+lIwHiDp7GSyKl4RMPQlk2zJUm9QxNQT2e3j3V56JtA9Ygq9fsv0O9zWKqqQyOrA VHcv2+FPOA+2FRhvVJJlvF/b8VYw8WwQHHnJ0Ne+AsdOSNhkZGOM1nJSz/SWxSy7Qx 2m6pMIccafWKw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zou Wei , Hulk Robot , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 09/55] mISDN: fix possible use-after-free in HFC_cleanup() Date: Tue, 6 Jul 2021 07:25:52 -0400 Message-Id: <20210706112638.2065023-9-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210706112638.2065023-1-sashal@kernel.org> References: <20210706112638.2065023-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zou Wei [ Upstream commit 009fc857c5f6fda81f2f7dd851b2d54193a8e733 ] This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself. Reported-by: Hulk Robot Signed-off-by: Zou Wei Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/isdn/hardware/mISDN/hfcpci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/isdn/hardware/mISDN/hfcpci.c b/drivers/isdn/hardware/mISDN/hfcpci.c index ebb3fa2e1d00..53349850f866 100644 --- a/drivers/isdn/hardware/mISDN/hfcpci.c +++ b/drivers/isdn/hardware/mISDN/hfcpci.c @@ -2348,7 +2348,7 @@ static void __exit HFC_cleanup(void) { if (timer_pending(&hfc_tl)) - del_timer(&hfc_tl); + del_timer_sync(&hfc_tl); pci_unregister_driver(&hfc_driver); } -- 2.30.2