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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 91D70C3A59E for ; Sat, 17 Aug 2019 08:09:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 52C2E2077C for ; Sat, 17 Aug 2019 08:09:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="PFmZ3tEw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52C2E2077C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DD2C76B000C; Sat, 17 Aug 2019 04:09:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D834B6B000D; Sat, 17 Aug 2019 04:09:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C99FF6B000E; Sat, 17 Aug 2019 04:09:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0088.hostedemail.com [216.40.44.88]) by kanga.kvack.org (Postfix) with ESMTP id A8EB36B000C for ; Sat, 17 Aug 2019 04:09:50 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 4D40C181AC9C9 for ; Sat, 17 Aug 2019 08:09:50 +0000 (UTC) X-FDA: 75831196140.28.songs74_38b4b3176575e X-HE-Tag: songs74_38b4b3176575e X-Filterd-Recvd-Size: 5023 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Sat, 17 Aug 2019 08:09:49 +0000 (UTC) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 469Xsk4XFmz9typx; Sat, 17 Aug 2019 10:09:46 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=PFmZ3tEw; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id sNvX-0_3f_4K; Sat, 17 Aug 2019 10:09:46 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 469Xsk3PNRz9typs; Sat, 17 Aug 2019 10:09:46 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1566029386; bh=pVI9gY6iiTOKFqgekWFv504Tf/QYksOUjRjQFOu2kD0=; h=Subject:To:References:From:Date:In-Reply-To:From; b=PFmZ3tEwbCcnorGnd5QrmBxwxFFSuDEhTO5ZjS4uBLNisb+UKUNsl94HoIWJQIWXF bOBEfuKIST6lerMbAPKSPdZzybS4qFVQ/HaIuSoZO3dGUCBsiLoMn8RJkAXWz528uW yVq0TMp+3G9mqWqk98b8zsX+IrJ6HBJWVGviJp44= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 9214B8B793; Sat, 17 Aug 2019 10:09:47 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id Lp6brMJxdad5; Sat, 17 Aug 2019 10:09:47 +0200 (CEST) Received: from [192.168.232.53] (unknown [192.168.232.53]) by messagerie.si.c-s.fr (Postfix) with ESMTP id EAA278B790; Sat, 17 Aug 2019 10:09:46 +0200 (CEST) Subject: Re: [Bug 204371] BUG kmalloc-4k (Tainted: G W ): Object padding overwritten To: bugzilla-daemon@bugzilla.kernel.org, linuxppc-dev@lists.ozlabs.org, Andrew Morton , Linux Memory Management List , linux-btrfs@vger.kernel.org, erhard_f@mailbox.org, Chris Mason , Josef Bacik , David Sterba , Michael Ellerman References: From: christophe leroy Message-ID: Date: Sat, 17 Aug 2019 10:09:46 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr X-Antivirus: Avast (VPS 190816-4, 16/08/2019), Outbound message X-Antivirus-Status: Clean Content-Transfer-Encoding: quoted-printable 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: Le 30/07/2019 =C3=A0 20:52, bugzilla-daemon@bugzilla.kernel.org a =C3=A9c= rit=C2=A0: > https://bugzilla.kernel.org/show_bug.cgi?id=3D204371 >=20 > --- Comment #2 from Andrew Morton (akpm@linux-foundation.org) --- > (switched to email. Please respond via emailed reply-to-all, not via t= he > bugzilla web interface). Reply all replies to bugzilla-daemon@bugzilla.kernel.org only. [...] >=20 > cc'ing various people here. Hum ... only got that email through the bugzilla interface, and CC'ed=20 people don't show up. >=20 > I suspect proc_cgroup_show() is innocent and that perhaps > bpf_prepare_filter() had a memory scribble. iirc there has been at > least one recent pretty serious bpf fix applied recently. Can others > please take a look? >=20 > (Seriously - please don't modify this report via the bugzilla web inter= face!) >=20 Haven't got the original CC'ed list, so please reply with missing Cc's=20 if any. We have well progressed on this case. Erhard made a relation being this "Object padding overwritten" issue=20 arising on any driver, and the presence of the BTRFS driver. Then he was able to bisect the issue to: commit 69d2480456d1baf027a86e530989d7bedd698d5f Author: David Sterba Date: Fri Jun 29 10:56:44 2018 +0200 btrfs: use copy_page for copying pages instead of memcpy Use the helper that's possibly optimized for full page copies. Signed-off-by: David Sterba After looking in the code, it has appeared that some of the said "pages"=20 were allocated with "kzalloc()". Using the patch https://patchwork.ozlabs.org/patch/1148033/ Erhard=20 confirmed that some btrfs functions were calling copy_page() with=20 misaligned destinations. copy_page(), at least on powerpc, expects cache aligned destination. The patch https://patchwork.ozlabs.org/patch/1148606/ fixes the issue. Christophe --- L'absence de virus dans ce courrier =C3=A9lectronique a =C3=A9t=C3=A9 v=C3= =A9rifi=C3=A9e par le logiciel antivirus Avast. https://www.avast.com/antivirus