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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS 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 7918AC388F9 for ; Fri, 6 Nov 2020 22:48:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A7E4320B1F for ; Fri, 6 Nov 2020 22:48:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="GgJzvJbY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7E4320B1F 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 8CD826B0036; Fri, 6 Nov 2020 17:48:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 856E26B005C; Fri, 6 Nov 2020 17:48:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6F8516B0068; Fri, 6 Nov 2020 17:48:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0091.hostedemail.com [216.40.44.91]) by kanga.kvack.org (Postfix) with ESMTP id 1D6AF6B0036 for ; Fri, 6 Nov 2020 17:48:15 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id AF749362D for ; Fri, 6 Nov 2020 22:48:14 +0000 (UTC) X-FDA: 77455483308.19.list39_3502ac3272d6 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin19.hostedemail.com (Postfix) with ESMTP id 93EB41AD1B2 for ; Fri, 6 Nov 2020 22:48:14 +0000 (UTC) X-HE-Tag: list39_3502ac3272d6 X-Filterd-Recvd-Size: 2232 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Fri, 6 Nov 2020 22:48:14 +0000 (UTC) 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 9578E2087E; Fri, 6 Nov 2020 22:48:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604702893; bh=Oj1ydksyNqQ3ZwyWkWH+O74qkDDreoYI/9+2rwNutow=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GgJzvJbYnUHZVh/KVjPbUkpsfTIS+ixIdR5hDbc8e6O11e3cdgusrJ+SXHU1mNK02 T1pf6Ysk+sGbT7IeHtbS79IjEOVb10BsqWj7Z/BpfjH8Hjsl5L51bZ3setY8WJNtnr JcdIhGHQmomXcxD8lLvJYy+d8B/elDLs+I2TO9iQ= Date: Fri, 6 Nov 2020 14:48:11 -0800 From: Andrew Morton To: =?ISO-8859-1?Q?"Christian_K=F6nig"?= Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org Subject: Re: [PATCH 1/2] mm: mmap: fix fput in error path v2 Message-Id: <20201106144811.cf228ca9278ec78887d42960@linux-foundation.org> In-Reply-To: <20201106114806.46015-2-christian.koenig@amd.com> References: <20201106114806.46015-1-christian.koenig@amd.com> <20201106114806.46015-2-christian.koenig@amd.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=ISO-8859-1 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: On Fri, 6 Nov 2020 12:48:05 +0100 "Christian K=F6nig" wrote: > Patch "495c10cc1c0c CHROMIUM: dma-buf: restore args..." > adds a workaround for a bug in mmap_region. >=20 > As the comment states ->mmap() callback can change > vma->vm_file and so we might call fput() on the wrong file. >=20 > Revert the workaround and proper fix this in mmap_region. >=20 Seems correct, best I can tell. Presumably all ->mmap() instances will correctly fput() to original file* if they're rewriting vma->vm_file.