From patchwork Sat Mar 13 05:08:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 400395 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED 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 C307DC432C3 for ; Sat, 13 Mar 2021 05:08:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA45864FC0 for ; Sat, 13 Mar 2021 05:08:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232230AbhCMFIM (ORCPT ); Sat, 13 Mar 2021 00:08:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:42176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232023AbhCMFIL (ORCPT ); Sat, 13 Mar 2021 00:08:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id AC18164F94; Sat, 13 Mar 2021 05:08:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1615612091; bh=CESRd6SNLsaOY2RX7+AT+TjD+Ud3fDWanSkhqCBWjIg=; h=Date:From:To:Subject:In-Reply-To:From; b=PdldyS3trAOVSGdcJ/vSyxcigYafByIrYREXBqfKO9CWcPb+CWEFmLQoA0Vms8ojK +1+9icXjWTlVmTNeEKRNomOzuASDLDT4zcuwPfsPtxGTSuELZuQpd/14smfNmhfk7c lpPqRD1nihnu2VRxSBSZLgeezRW9ut8+G0XcXJIY= Date: Fri, 12 Mar 2021 21:08:10 -0800 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, aryabinin@virtuozzo.com, Branislav.Rankov@arm.com, catalin.marinas@arm.com, dvyukov@google.com, elver@google.com, eugenis@google.com, glider@google.com, hch@infradead.org, kevin.brodsky@arm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, pcc@google.com, stable@vger.kernel.org, torvalds@linux-foundation.org, vincenzo.frascino@arm.com, will.deacon@arm.com Subject: [patch 20/29] kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC Message-ID: <20210313050810.cdPfxpuDx%akpm@linux-foundation.org> In-Reply-To: <20210312210632.9b7d62973d72a56fb13c7a03@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andrey Konovalov Subject: kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC 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. Link: https://lkml.kernel.org/r/24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com Fixes: 94ab5b61ee16 ("kasan, arm64: enable CONFIG_KASAN_HW_TAGS") Signed-off-by: Andrey Konovalov Cc: Catalin Marinas Cc: Will Deacon Cc: Vincenzo Frascino Cc: Dmitry Vyukov Cc: Andrey Ryabinin Cc: Alexander Potapenko Cc: Marco Elver Cc: Peter Collingbourne Cc: Evgenii Stepanov Cc: Branislav Rankov Cc: Kevin Brodsky Cc: Christoph Hellwig Cc: Signed-off-by: Andrew Morton --- mm/page_alloc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/mm/page_alloc.c~kasan-mm-fix-crash-with-hw_tags-and-debug_pagealloc +++ a/mm/page_alloc.c @@ -1282,6 +1282,12 @@ static __always_inline bool free_pages_p 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); + + /* * arch_free_page() can make the page's contents inaccessible. s390 * does this. So nothing which can access the page's contents should * happen after this. @@ -1290,8 +1296,6 @@ static __always_inline bool free_pages_p debug_pagealloc_unmap_pages(page, 1 << order); - kasan_free_nondeferred_pages(page, order); - return true; }