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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS 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 CEE00C433DB for ; Fri, 5 Mar 2021 23:50:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96EA9650B5 for ; Fri, 5 Mar 2021 23:50:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229597AbhCEXuB (ORCPT ); Fri, 5 Mar 2021 18:50:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:57230 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229697AbhCEXt5 (ORCPT ); Fri, 5 Mar 2021 18:49:57 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A66BD65073; Fri, 5 Mar 2021 23:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614988197; bh=T1WRciFZ6SROSTvnq6Id8/sVq43F1qvTO0XybjxDSNs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=2J4OjFKKqN1PUcQG2vhC4e4UvgSYhgzDkv/q78FCoHnZt4B511g2fPskOH7C/cfeo TcYzPlKhPlrZOeiNlCy5ilQYwSnTfvDkR+cfhwC8OULkj7HVL5EAcsjHHfmQnQs2MY ERQVAQ7Uq32B4Ha2x56xXw/JUWk75dvlyr/B1DSs= Date: Fri, 5 Mar 2021 15:49:56 -0800 From: Andrew Morton To: Andrey Konovalov Cc: Alexander Potapenko , Catalin Marinas , Will Deacon , Vincenzo Frascino , Dmitry Vyukov , Andrey Ryabinin , Marco Elver , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC Message-Id: <20210305154956.3bbfcedab3f549b708d5e2fa@linux-foundation.org> In-Reply-To: <24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com> References: <24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 6 Mar 2021 00:36:33 +0100 Andrey Konovalov wrote: > Currently, kasan_free_nondeferred_pages()->kasan_free_pages() is called > after debug_pagealloc_unmap_pages(). This causes a crash when > debug_pagealloc is enabled, as HW_TAGS KASAN can't set tags on an > unmapped page. > > This patch puts kasan_free_nondeferred_pages() before > debug_pagealloc_unmap_pages() and arch_free_page(), which can also make > the page unavailable. > > ... > > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1304,6 +1304,12 @@ static __always_inline bool free_pages_prepare(struct page *page, > > kernel_poison_pages(page, 1 << order); > > + /* > + * With hardware tag-based KASAN, memory tags must be set before the > + * page becomes unavailable via debug_pagealloc or arch_free_page. > + */ > + kasan_free_nondeferred_pages(page, order, fpi_flags); > + > /* > * arch_free_page() can make the page's contents inaccessible. s390 > * does this. So nothing which can access the page's contents should > @@ -1313,8 +1319,6 @@ static __always_inline bool free_pages_prepare(struct page *page, > > debug_pagealloc_unmap_pages(page, 1 << order); > > - kasan_free_nondeferred_pages(page, order, fpi_flags); > - > return true; > } kasan_free_nondeferred_pages() has only two args in current mainline. I fixed that in the obvious manner... 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=-8.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2F137C433E0 for ; Fri, 5 Mar 2021 23:51:44 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 B6AF5650AA for ; Fri, 5 Mar 2021 23:51:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B6AF5650AA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.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=desiato.20200630; 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: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jNIlpfXFnsSDPglnStZ8RrBJrSt6h3V/ofU4LAg3Ys4=; b=lrXIsKRdjirkEe+rjXdkFCCjY w5EkHSgSQJaHWT3OHlT8BjepHaO10RAq8aWgmnWz3l7LElJ6dBsVYNx5MB5W4hvu6w0OQds5TGBz+ rWoSCguwk0+3ueBun0N4TOaRtO1TzyHrZN7pbgOtiIcTWg6EvzoggqwFyHTu9Ar5HmySiqy5oLkp+ HkofnImerhNTkCxUFifVF5lkfY4VEr/BeNxaY+8xAfIEu4thfhSmzempv6MxRyqf+dZWD9MGLioxQ e9Hqz7IqCqYeQoEBLzElWdFuC87KFKE8rfGO46/d3JCL+X2CuSTlXzUdsicDawLmcMPEaKWIYC7w+ 253eeJTPg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lIKCt-00HCN7-8p; Fri, 05 Mar 2021 23:50:08 +0000 Received: from mail.kernel.org ([198.145.29.99]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lIKCk-00HCJb-N7 for linux-arm-kernel@lists.infradead.org; Fri, 05 Mar 2021 23:50:00 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id A66BD65073; Fri, 5 Mar 2021 23:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614988197; bh=T1WRciFZ6SROSTvnq6Id8/sVq43F1qvTO0XybjxDSNs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=2J4OjFKKqN1PUcQG2vhC4e4UvgSYhgzDkv/q78FCoHnZt4B511g2fPskOH7C/cfeo TcYzPlKhPlrZOeiNlCy5ilQYwSnTfvDkR+cfhwC8OULkj7HVL5EAcsjHHfmQnQs2MY ERQVAQ7Uq32B4Ha2x56xXw/JUWk75dvlyr/B1DSs= Date: Fri, 5 Mar 2021 15:49:56 -0800 From: Andrew Morton To: Andrey Konovalov Cc: Alexander Potapenko , Catalin Marinas , Will Deacon , Vincenzo Frascino , Dmitry Vyukov , Andrey Ryabinin , Marco Elver , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC Message-Id: <20210305154956.3bbfcedab3f549b708d5e2fa@linux-foundation.org> In-Reply-To: <24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com> References: <24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210305_234959_119220_AED31510 X-CRM114-Status: GOOD ( 14.08 ) 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 On Sat, 6 Mar 2021 00:36:33 +0100 Andrey Konovalov wrote: > Currently, kasan_free_nondeferred_pages()->kasan_free_pages() is called > after debug_pagealloc_unmap_pages(). This causes a crash when > debug_pagealloc is enabled, as HW_TAGS KASAN can't set tags on an > unmapped page. > > This patch puts kasan_free_nondeferred_pages() before > debug_pagealloc_unmap_pages() and arch_free_page(), which can also make > the page unavailable. > > ... > > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1304,6 +1304,12 @@ static __always_inline bool free_pages_prepare(struct page *page, > > kernel_poison_pages(page, 1 << order); > > + /* > + * With hardware tag-based KASAN, memory tags must be set before the > + * page becomes unavailable via debug_pagealloc or arch_free_page. > + */ > + kasan_free_nondeferred_pages(page, order, fpi_flags); > + > /* > * arch_free_page() can make the page's contents inaccessible. s390 > * does this. So nothing which can access the page's contents should > @@ -1313,8 +1319,6 @@ static __always_inline bool free_pages_prepare(struct page *page, > > debug_pagealloc_unmap_pages(page, 1 << order); > > - kasan_free_nondeferred_pages(page, order, fpi_flags); > - > return true; > } kasan_free_nondeferred_pages() has only two args in current mainline. I fixed that in the obvious manner... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel