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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, 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 9337AC636CB for ; Thu, 15 Jul 2021 19:04:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E44761407 for ; Thu, 15 Jul 2021 19:04:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242085AbhGOTHk (ORCPT ); Thu, 15 Jul 2021 15:07:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:33734 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241774AbhGOS5T (ORCPT ); Thu, 15 Jul 2021 14:57:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5E37660D07; Thu, 15 Jul 2021 18:54:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626375265; bh=1t40GFUdfFHXYov82Lchb4r/peMxoMO2yy/t5xvZifk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N5X1vlwK3Ur0TlH52xhAj61jiSzv+wEUnjTBhxsxnAmwqxUlEHsKjVE75hYE+1pfx j1mZj5cBTqaFFESH/xblffkPyTY/gQvtNMkVeZ7fJtKZ1Lfkzk9YMGLaxI5QCnmtKq GDjiPfvjZANs4nZ9rTp4Y+lBdY/o9OMuohdqtWmo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hulk Robot , Zou Wei , "David S. Miller" , Sasha Levin Subject: [PATCH 5.12 015/242] atm: nicstar: Fix possible use-after-free in nicstar_cleanup() Date: Thu, 15 Jul 2021 20:36:17 +0200 Message-Id: <20210715182554.433921216@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182551.731989182@linuxfoundation.org> References: <20210715182551.731989182@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zou Wei [ Upstream commit 34e7434ba4e97f4b85c1423a59b2922ba7dff2ea ] 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/atm/nicstar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/atm/nicstar.c b/drivers/atm/nicstar.c index 5c7e4df159b9..b015c3e14336 100644 --- a/drivers/atm/nicstar.c +++ b/drivers/atm/nicstar.c @@ -299,7 +299,7 @@ static void __exit nicstar_cleanup(void) { XPRINTK("nicstar: nicstar_cleanup() called.\n"); - del_timer(&ns_timer); + del_timer_sync(&ns_timer); pci_unregister_driver(&nicstar_driver); -- 2.30.2