From patchwork Fri Apr 30 05:55:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12232359 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=-15.7 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_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 0CD9CC433ED for ; Fri, 30 Apr 2021 05:55:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9D52961462 for ; Fri, 30 Apr 2021 05:55:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D52961462 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3DBD46B00AB; Fri, 30 Apr 2021 01:55:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 366A46B00AC; Fri, 30 Apr 2021 01:55:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 144A66B00AD; Fri, 30 Apr 2021 01:55:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0129.hostedemail.com [216.40.44.129]) by kanga.kvack.org (Postfix) with ESMTP id E82426B00AB for ; Fri, 30 Apr 2021 01:55:13 -0400 (EDT) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 9FBB4181AF5C3 for ; Fri, 30 Apr 2021 05:55:13 +0000 (UTC) X-FDA: 78087970506.01.76F7DA8 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf15.hostedemail.com (Postfix) with ESMTP id C71D7A0003B6 for ; Fri, 30 Apr 2021 05:55:08 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 697BB6145D; Fri, 30 Apr 2021 05:55:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1619762112; bh=OKK5pQVSNMMbAs7vOJpdEv9yRXMiToy9D/a6gMX6LvU=; h=Date:From:To:Subject:In-Reply-To:From; b=0Q0JwSxGVUpDVdYigBHJHRhN4n0ExS9K4HwAwfb/fZJb2DXDE7FpPVW29MMtEdJgi LAUJ0GsN+yhRMn4R2OjWZAouTA1Y60YPSvOWwD022Jq+tfNCI4tVya9qNFvCFeFz+u ffKdCN9WQMEZJ+hBLhShrXSd0MJPKEAGtxuGinnc= Date: Thu, 29 Apr 2021 22:55:12 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, slyfox@gentoo.org, torvalds@linux-foundation.org, vbabka@suse.cz Subject: [patch 039/178] mm: page_poison: print page info when corruption is caught Message-ID: <20210430055512.z1ThP17xP%akpm@linux-foundation.org> In-Reply-To: <20210429225251.02b6386d21b69255b4f6c163@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: C71D7A0003B6 Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=0Q0JwSxG; dmarc=none; spf=pass (imf15.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Stat-Signature: hbbdzk476i31548it8zottpbr9wctbb6 Received-SPF: none (linux-foundation.org>: No applicable sender policy available) receiver=imf15; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619762108-281393 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Sergei Trofimovich Subject: mm: page_poison: print page info when corruption is caught When page_poison detects page corruption it's useful to see who freed a page recently to have a guess where write-after-free corruption happens. After this change corruption report has extra page data. Example report from real corruption (includes only page_pwner part): pagealloc: memory corruption e00000014cd61d10: 11 00 00 00 00 00 00 00 30 1d d2 ff ff 0f 00 60 ........0......` e00000014cd61d20: b0 1d d2 ff ff 0f 00 60 90 fe 1c 00 08 00 00 20 .......`....... ... CPU: 1 PID: 220402 Comm: cc1plus Not tainted 5.12.0-rc5-00107-g9720c6f59ecf #245 Hardware name: hp server rx3600, BIOS 04.03 04/08/2008 ... Call Trace: [] show_stack+0x90/0xc0 [] dump_stack+0x150/0x1c0 [] __kernel_unpoison_pages+0x410/0x440 [] get_page_from_freelist+0x1460/0x2ca0 [] __alloc_pages_nodemask+0x3c0/0x660 [] alloc_pages_vma+0xb0/0x500 [] __handle_mm_fault+0x1230/0x1fe0 [] handle_mm_fault+0x310/0x4e0 [] ia64_do_page_fault+0x1f0/0xb80 [] ia64_leave_kernel+0x0/0x270 page_owner tracks the page as freed page allocated via order 0, migratetype Movable, gfp_mask 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 37, ts 8173444098740 __reset_page_owner+0x40/0x200 free_pcp_prepare+0x4d0/0x600 free_unref_page+0x20/0x1c0 __put_page+0x110/0x1a0 migrate_pages+0x16d0/0x1dc0 compact_zone+0xfc0/0x1aa0 proactive_compact_node+0xd0/0x1e0 kcompactd+0x550/0x600 kthread+0x2c0/0x2e0 call_payload+0x50/0x80 Here we can see that page was freed by page migration but something managed to write to it afterwards. [slyfox@gentoo.org: s/dump_page_owner/dump_page/, per Vlastimil] Link: https://lkml.kernel.org/r/20210407230800.1086854-1-slyfox@gentoo.org Link: https://lkml.kernel.org/r/20210404141735.2152984-1-slyfox@gentoo.org Signed-off-by: Sergei Trofimovich Acked-by: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/page_poison.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/mm/page_poison.c~mm-page_poison-print-page-owner-info-when-corruption-is-caught +++ a/mm/page_poison.c @@ -2,6 +2,7 @@ #include #include #include +#include #include #include #include @@ -45,7 +46,7 @@ static bool single_bit_flip(unsigned cha return error && !(error & (error - 1)); } -static void check_poison_mem(unsigned char *mem, size_t bytes) +static void check_poison_mem(struct page *page, unsigned char *mem, size_t bytes) { static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 10); unsigned char *start; @@ -70,6 +71,7 @@ static void check_poison_mem(unsigned ch print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, start, end - start + 1, 1); dump_stack(); + dump_page(page, "pagealloc: corrupted page details"); } static void unpoison_page(struct page *page) @@ -83,7 +85,7 @@ static void unpoison_page(struct page *p * that is freed to buddy. Thus no extra check is done to * see if a page was poisoned. */ - check_poison_mem(kasan_reset_tag(addr), PAGE_SIZE); + check_poison_mem(page, kasan_reset_tag(addr), PAGE_SIZE); kasan_enable_current(); kunmap_atomic(addr); }