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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 A8DD9C46471 for ; Tue, 7 Aug 2018 18:55:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DC152172F for ; Tue, 7 Aug 2018 18:55:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DC152172F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404273AbeHGVKn (ORCPT ); Tue, 7 Aug 2018 17:10:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:33582 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733122AbeHGVKm (ORCPT ); Tue, 7 Aug 2018 17:10:42 -0400 Received: from localhost (unknown [194.244.16.108]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id AE5743EE; Tue, 7 Aug 2018 18:54:58 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Konstantin Khlebnikov , Catalin Marinas , Andrew Morton , Linus Torvalds , "Srivatsa S. Bhat" Subject: [PATCH 4.9 14/17] kmemleak: clear stale pointers from task stacks Date: Tue, 7 Aug 2018 20:51:50 +0200 Message-Id: <20180807172342.867453448@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180807172342.071526922@linuxfoundation.org> References: <20180807172342.071526922@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konstantin Khlebnikov commit ca182551857cc2c1e6a2b7f1e72090a137a15008 upstream. Kmemleak considers any pointers on task stacks as references. This patch clears newly allocated and reused vmap stacks. Link: http://lkml.kernel.org/r/150728990124.744199.8403409836394318684.stgit@buzz Signed-off-by: Konstantin Khlebnikov Acked-by: Catalin Marinas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [ Srivatsa: Backported to 4.9.y ] Signed-off-by: Srivatsa S. Bhat Signed-off-by: Greg Kroah-Hartman --- include/linux/thread_info.h | 2 +- kernel/fork.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -59,7 +59,7 @@ extern long do_no_restart_syscall(struct #ifdef __KERNEL__ -#ifdef CONFIG_DEBUG_STACK_USAGE +#if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) || IS_ENABLED(CONFIG_DEBUG_KMEMLEAK) # define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \ __GFP_ZERO) #else --- a/kernel/fork.c +++ b/kernel/fork.c @@ -184,6 +184,10 @@ static unsigned long *alloc_thread_stack continue; this_cpu_write(cached_stacks[i], NULL); +#ifdef CONFIG_DEBUG_KMEMLEAK + /* Clear stale pointers from reused stack. */ + memset(s->addr, 0, THREAD_SIZE); +#endif tsk->stack_vm_area = s; local_irq_enable(); return s->addr;