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=-17.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_NONE,URIBL_BLOCKED,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 BCA8EC07E9E for ; Sat, 10 Jul 2021 23:54:47 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9550E611B0 for ; Sat, 10 Jul 2021 23:54:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9550E611B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EShiZGduS9nNF99hj0S+xedxcOHLd7gM4oHArK8bdo4=; b=jdg/MuCoX5Y+5s rsNx7b5pyjyzMonCqaf8+13BTJjRZ8eTdMiu5FYfBKV+PBArRElsDi03vot5GPZ8G+ht9JpKoKtQC UyoYa/qg1HsafuO9fNSTc6od+6vTZRxztDtvpNkAM7Fc1HLdPb/Wos59FPmk/wGI0nKlVFa7+u35k KOcx8ttl2gCRuskDKRCAoNHXeSw6aDdS3VmDtahtSjSarElf4IvpHO5bgw/FZu/BCqyQdG2lPv5d1 TkZrqqnc/M/zoflIsZ4fOULQP0n1M4caknwe2aYpNRKSRmLilO0tEnHFIaD61ed1ALeVN+VtVprI8 Ut1FwEciVHPJYq/dlQnw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2MmV-004JhA-QS; Sat, 10 Jul 2021 23:53:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2Mkk-004IS8-CA for linux-arm-kernel@lists.infradead.org; Sat, 10 Jul 2021 23:51:23 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0101B61362; Sat, 10 Jul 2021 23:51:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625961082; bh=eWAWdoYUyGT4tcyRnagC6znYfXGQBgaN1dR66rV/snc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bFFZEr5Fh0o47HJpzIS5LhZXyv6y47GFvEVMyy8ukL04JasTPnRA7uCht3oZdKgNV mY/AVta6r3yHJCzXoz9FOqRezwJIRDo7CH3oAWlIFJ3fPz8LHDkJxYWCOGYeu8RjKm BVU2ZEzBgUU6Rsd+9A/UU+aoXo1pMVhu4uaSEweMw7YXSGb4lT+zQze1A1Gz2grpfs kz3kSukTfTx1DL0QgBvUbhpTUt8g+4b3IWqK5tvsCBwF26ChX3yETBPbAtz1Xiy9QZ LwNU/WEGjkJ8MEcaJfxcztfxkMR1SYc/YW7lAnEk7/ELaLqN3TmQuC0eMRW7AXTSpS TbofHxr3V3Vsw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zou Wei , Hulk Robot , Guenter Roeck , Vladimir Zapolskiy , Wim Van Sebroeck , Sasha Levin , linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 11/28] watchdog: Fix possible use-after-free by calling del_timer_sync() Date: Sat, 10 Jul 2021 19:50:50 -0400 Message-Id: <20210710235107.3221840-11-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710235107.3221840-1-sashal@kernel.org> References: <20210710235107.3221840-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210710_165122_497447_ED8132E3 X-CRM114-Status: GOOD ( 13.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Zou Wei [ Upstream commit d0212f095ab56672f6f36aabc605bda205e1e0bf ] This driver'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 Reviewed-by: Guenter Roeck Acked-by: Vladimir Zapolskiy Link: https://lore.kernel.org/r/1620802676-19701-1-git-send-email-zou_wei@huawei.com Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- drivers/watchdog/lpc18xx_wdt.c | 2 +- drivers/watchdog/w83877f_wdt.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/lpc18xx_wdt.c b/drivers/watchdog/lpc18xx_wdt.c index 78cf11c94941..60b6d74f267d 100644 --- a/drivers/watchdog/lpc18xx_wdt.c +++ b/drivers/watchdog/lpc18xx_wdt.c @@ -292,7 +292,7 @@ static int lpc18xx_wdt_remove(struct platform_device *pdev) struct lpc18xx_wdt_dev *lpc18xx_wdt = platform_get_drvdata(pdev); dev_warn(&pdev->dev, "I quit now, hardware will probably reboot!\n"); - del_timer(&lpc18xx_wdt->timer); + del_timer_sync(&lpc18xx_wdt->timer); return 0; } diff --git a/drivers/watchdog/w83877f_wdt.c b/drivers/watchdog/w83877f_wdt.c index 6eb5185d6ea6..d9addf06b44d 100644 --- a/drivers/watchdog/w83877f_wdt.c +++ b/drivers/watchdog/w83877f_wdt.c @@ -166,7 +166,7 @@ static void wdt_startup(void) static void wdt_turnoff(void) { /* Stop the timer */ - del_timer(&timer); + del_timer_sync(&timer); wdt_change(WDT_DISABLE); -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel