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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 613CDC433DF for ; Fri, 7 Aug 2020 06:25:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 332D0221E5 for ; Fri, 7 Aug 2020 06:25:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781500; bh=Akj9TznAPFn9H7V3OZSpI9Z9g20j0XMLIiMYF6UzH6o=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=EXgdg0QVraS7NUeO/8/4UB1eXRD13auMVutphAWRU1zWfn6fSpF5lP6KpFJemvkjG +q4lRxvo5GxcxefNU5u/jjoaKVI3Qw7ArZ2D0KJkdn7xsJN+ji9/HAOirulgsC8nqw KvogTiM9osuygnZnz0fIseoZslMyo5WV7SbjagYk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725845AbgHGGY7 (ORCPT ); Fri, 7 Aug 2020 02:24:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:33754 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725379AbgHGGY7 (ORCPT ); Fri, 7 Aug 2020 02:24:59 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5B3B422CB3; Fri, 7 Aug 2020 06:24:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781499; bh=Akj9TznAPFn9H7V3OZSpI9Z9g20j0XMLIiMYF6UzH6o=; h=Date:From:To:Subject:In-Reply-To:From; b=pRaMB8eiftmaZgNKgmVV5+sB7eMSqohulQ48u2/QlZoHN6rNQssYMp35O53AsZAGL n8QRaEHzlLsV5K6iTY5avdsklzN+a5S3t7c8Qm9AUgql/bfDv+XN8ql/2KJrEyXJl1 eMzPQE2r3MgRNBbc3opQi7npICMphsVnTTt1tt+Q= Date: Thu, 06 Aug 2020 23:24:57 -0700 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, ardb@kernel.org, aryabinin@virtuozzo.com, catalin.marinas@arm.com, dvyukov@google.com, elver@google.com, glider@google.com, lenaptr@google.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vincenzo.frascino@arm.com, walter-zh.wu@mediatek.com Subject: [patch 136/163] kasan: don't tag stacks allocated with pagealloc Message-ID: <20200807062457.PNGMqcze5%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Andrey Konovalov Subject: kasan: don't tag stacks allocated with pagealloc Patch series "kasan: support stack instrumentation for tag-based mode", v2. This patch (of 5): Prepare Software Tag-Based KASAN for stack tagging support. With Tag-Based KASAN when kernel stacks are allocated via pagealloc (which happens when CONFIG_VMAP_STACK is not enabled), they get tagged. KASAN instrumentation doesn't expect the sp register to be tagged, and this leads to false-positive reports. Fix by resetting the tag of kernel stack pointers after allocation. Link: http://lkml.kernel.org/r/cover.1596199677.git.andreyknvl@google.com Link: http://lkml.kernel.org/r/cover.1596544734.git.andreyknvl@google.com Link: http://lkml.kernel.org/r/12d8c678869268dd0884b01271ab592f30792abf.1596544734.git.andreyknvl@google.com Link: http://lkml.kernel.org/r/01c678b877755bcf29009176592402cdf6f2cb15.1596199677.git.andreyknvl@google.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=203497 Signed-off-by: Andrey Konovalov Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Marco Elver Cc: Walter Wu Cc: Elena Petrova Cc: Vincenzo Frascino Cc: Catalin Marinas Cc: Ard Biesheuvel Signed-off-by: Andrew Morton --- kernel/fork.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/fork.c~kasan-dont-tag-stacks-allocated-with-pagealloc +++ a/kernel/fork.c @@ -261,7 +261,7 @@ static unsigned long *alloc_thread_stack THREAD_SIZE_ORDER); if (likely(page)) { - tsk->stack = page_address(page); + tsk->stack = kasan_reset_tag(page_address(page)); return tsk->stack; } return NULL; @@ -302,6 +302,7 @@ static unsigned long *alloc_thread_stack { unsigned long *stack; stack = kmem_cache_alloc_node(thread_stack_cache, THREADINFO_GFP, node); + stack = kasan_reset_tag(stack); tsk->stack = stack; return stack; } _