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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 832ADC4332F for ; Tue, 29 Nov 2022 04:04:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AA2246B0071; Mon, 28 Nov 2022 23:04:47 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A525F6B0073; Mon, 28 Nov 2022 23:04:47 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 941416B0074; Mon, 28 Nov 2022 23:04:47 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 852376B0071 for ; Mon, 28 Nov 2022 23:04:47 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 4E37580DD4 for ; Tue, 29 Nov 2022 04:04:47 +0000 (UTC) X-FDA: 80185138614.20.ABB664F Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) by imf30.hostedemail.com (Postfix) with ESMTP id 9A5AC80012 for ; Tue, 29 Nov 2022 04:04:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=SFmlSqgAPWtwF6quHxtAG0npFApZzjL0nMEqzkSuKeo=; b=faz6vq8W5eO3z9yrIbJe5AjURg PsyOFeSQqLqXlIam1NF0aTcptLlgTGM5w7eR/rwd1gZK8VHc0FjOQClBgsVCuC5rpY8Rk7FaiW7Zu okMu2mTmJV8kmNuLJLCFp5nqCXBsuLLdE6Gp6+7cNuWMeokCNkBah22G9pkj3jsDb2KVBzlJRtLnP 8/eDWhMjN4mDRox1yk69lL6t1YVT+mpdSVf7aBuEXvQmZOvjNARFScmy0dl74YanIoDujK9iwOHAr JEatjFXhhjJBSB9zqfnK2M1K61uH/Hgzu+ZP3bU6d7I9XDNJpvdseX9D8Y+rf+tXbDsJwNHpW/p9n 8HLgMm1g==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1ozrrH-007Zj5-1M; Tue, 29 Nov 2022 04:04:35 +0000 Date: Tue, 29 Nov 2022 04:04:35 +0000 From: Al Viro To: syzbot Cc: akpm@linux-foundation.org, dan.j.williams@intel.com, hch@lst.de, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org Subject: Re: [syzbot] WARNING in iov_iter_revert (3) Message-ID: References: <000000000000519d0205ee4ba094@google.com> <000000000000f5ecad05ee8fccf0@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000f5ecad05ee8fccf0@google.com> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1669694687; a=rsa-sha256; cv=none; b=nGVl7TGedy62+8efDzQY7m5T22CY/d/XttcHmhriLATWs3mSEsLRcNIXLXD4pJfZ9BQMP9 /56W5eJ4V5spK3Htr2Ss9TnkfTr8lltOpIc/pg1mNrGpi1jhNc1juDp2uX3cT7NXE3Dwpb imj+Ffw9R7bqyYkZ19XLW/knRmFHDog= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=faz6vq8W; spf=none (imf30.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1669694687; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=SFmlSqgAPWtwF6quHxtAG0npFApZzjL0nMEqzkSuKeo=; b=KicwfT6jLXHYj3q6hweyd1bLZY3RCe4dkg/365XRpBAiPSHVnrU2FNvgcL4WlT9Yrul4I6 8IPuQScXP/Cjlpq3Pk5usldwxZK2PnGqSniu2cUeU3Me3hoTT06pyM6RhkYPK7Dkp9glmJ ntoe709ppKTVIJX1VDdzqir/wgOurU8= X-Stat-Signature: zguk633jocjq8ydfwa69r31s1emkiwu7 X-Rspamd-Queue-Id: 9A5AC80012 X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=faz6vq8W; spf=none (imf30.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk X-Rspamd-Server: rspam05 X-HE-Tag: 1669694686-523182 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 Mon, Nov 28, 2022 at 02:57:49PM -0800, syzbot wrote: > syzbot has found a reproducer for the following issue on: [snip] > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17219fbb880000 "syz_mount_image$ntfs3(" followed by arseloads of garbage. And the thing conspiciously missing? Why, any ntfs3 maintainers in Cc... Or lists, for that matter... > generic_file_read_iter+0x3d4/0x540 mm/filemap.c:2804 > do_iter_read+0x6e3/0xc10 fs/read_write.c:796 > vfs_readv fs/read_write.c:916 [inline] > do_preadv+0x1f4/0x330 fs/read_write.c:1008 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd At a guess - something's screwed in ntfs3 ->direct_IO() (return value, most likely). And something's screwed in syzbot. If you are fuzzing some filesystem, YOU REALLY OUGHT TO CC THE MAINTAINERS OF THAT FILESYSTEM. Even if nothing in the stack trace happens to be in that fs. Folks, it's that simple - "our bot needs to remember that fuzzing $FS automatically puts maintainers of $FS into the set of people we need to Cc" vs. "maintainers of each filesystem need to dig into every syzbot posting on fsdevel (and follow links, no less) to check if their fs might be involved". If you can't be bothered to take care of the former, why would you expect $BIGNUM people to bother with the latter, again and again and again? Fix your bot, already. It's not the first time this had been brought to your attention and the problem is still there.