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=-4.0 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 91EA6C433E0 for ; Mon, 20 Jul 2020 23:51:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1ECB522B4D for ; Mon, 20 Jul 2020 23:51:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="vigIZWau" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1ECB522B4D 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 797128D0003; Mon, 20 Jul 2020 19:51:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 748368D0002; Mon, 20 Jul 2020 19:51:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6101C8D0003; Mon, 20 Jul 2020 19:51:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0138.hostedemail.com [216.40.44.138]) by kanga.kvack.org (Postfix) with ESMTP id 4978E8D0002 for ; Mon, 20 Jul 2020 19:51:47 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C189A180ACEEC for ; Mon, 20 Jul 2020 23:51:46 +0000 (UTC) X-FDA: 77060104212.09.slope67_35085f626f28 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 98BFF180ACF0E for ; Mon, 20 Jul 2020 23:51:46 +0000 (UTC) X-HE-Tag: slope67_35085f626f28 X-Filterd-Recvd-Size: 7524 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf50.hostedemail.com (Postfix) with ESMTP for ; Mon, 20 Jul 2020 23:51:46 +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 DE7DA208E4; Mon, 20 Jul 2020 23:51:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595289105; bh=7ruEEyKDUeYqw7QTMZfSVf0o3+tXFE6jymo2C5c1vDA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=vigIZWauYeJjqcJLOmY21S4+ieHufF0KzoPQtCFsoYZikeJcCItEoqiDzxWfjzJ4L CCTGDKwWEXkIVnZ3ZjfFbI0ZMZk4NUYjPhYjJGyoEOqJA/+dDuZ4LHPZ/wycAjslmQ UUfxBqUqlaSpzZJ132C/8qiw5mg9Guv+GcWQFJZw= Date: Mon, 20 Jul 2020 16:51:44 -0700 From: Andrew Morton To: syzbot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, Matthew Wilcox , "Kirill A. Shutemov" , Ralph Campbell , David Hildenbrand , Mike Kravetz Subject: Re: kernel BUG at include/linux/swapops.h:LINE! Message-Id: <20200720165144.93189f7825bd28e234a42cb8@linux-foundation.org> In-Reply-To: <0000000000004c38cd05aad1d13f@google.com> References: <000000000000bc4fd705a6e090e2@google.com> <0000000000004c38cd05aad1d13f@google.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=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 98BFF180ACF0E X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000004, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sun, 19 Jul 2020 14:10:19 -0700 syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 4c43049f Add linux-next specific files for 20200716 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=12c56087100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=2c76d72659687242 > dashboard link: https://syzkaller.appspot.com/bug?extid=c48f34012b06c4ac67dd > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1344abeb100000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+c48f34012b06c4ac67dd@syzkaller.appspotmail.com Thanks. __handle_mm_fault ->pmd_migration_entry_wait ->migration_entry_to_page stumbled onto an unlocked page. I don't immediately see a cause. Perhaps Matthew's "THP prep patches", perhaps something else. Is it possible to perform a bisection? > ------------[ cut here ]------------ > kernel BUG at include/linux/swapops.h:197! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 19938 Comm: syz-executor.2 Not tainted 5.8.0-rc5-next-20200716-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:migration_entry_to_page include/linux/swapops.h:197 [inline] > RIP: 0010:migration_entry_to_page include/linux/swapops.h:190 [inline] > RIP: 0010:pmd_migration_entry_wait+0x493/0x520 mm/migrate.c:368 > Code: 4d 8d 66 ff e9 1f fe ff ff e8 b9 c4 be ff 49 8d 5f ff e9 58 fe ff ff e8 ab c4 be ff 4d 8d 66 ff e9 a9 fe ff ff e8 9d c4 be ff <0f> 0b e8 96 c4 be ff 0f 0b e8 8f c4 be ff 4c 8d 65 ff eb a7 48 89 > RSP: 0018:ffffc9001095fb70 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81b56a24 > RDX: ffff888092022240 RSI: ffffffff81b56b43 RDI: 0000000000000001 > RBP: ffffea0008468080 R08: 0000000000000000 R09: ffffea0008468087 > R10: 0000000000000000 R11: 0000000000000000 R12: ffffea0008468080 > R13: ffff888015d2e0c0 R14: 0000000000000000 R15: 0000000000000000 > FS: 00007f55eb477700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020000080 CR3: 000000021ad87000 CR4: 00000000001526e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > __handle_mm_fault mm/memory.c:4349 [inline] > handle_mm_fault+0x23cf/0x45e0 mm/memory.c:4465 > do_user_addr_fault+0x598/0xbf0 arch/x86/mm/fault.c:1294 > handle_page_fault arch/x86/mm/fault.c:1351 [inline] > exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1404 > asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:544 > RIP: 0010:copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:91 > Code: 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76 40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a > RSP: 0018:ffffc9001095fe48 EFLAGS: 00010202 > RAX: 0000000000000001 RBX: 0000000020000080 RCX: 0000000000000001 > RDX: 0000000000000000 RSI: ffffc9001095fea8 RDI: 0000000020000080 > RBP: ffffc9001095fea8 R08: 0000000400000003 R09: ffffc9001095feaf > R10: fffff5200212bfd5 R11: 0000000000000000 R12: 0000000000000008 > R13: 0000000020000088 R14: 00007ffffffff000 R15: 0000000000000000 > copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] > raw_copy_to_user arch/x86/include/asm/uaccess_64.h:74 [inline] > _copy_to_user+0x11e/0x160 lib/usercopy.c:30 > copy_to_user include/linux/uaccess.h:168 [inline] > do_pipe2+0x128/0x1b0 fs/pipe.c:1014 > __do_sys_pipe fs/pipe.c:1035 [inline] > __se_sys_pipe fs/pipe.c:1033 [inline] > __x64_sys_pipe+0x2f/0x40 fs/pipe.c:1033 > do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x45c1d9 > Code: Bad RIP value. > RSP: 002b:00007f55eb476c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000016 > RAX: ffffffffffffffda RBX: 0000000000022ac0 RCX: 000000000045c1d9 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000080 > RBP: 000000000078c070 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c > R13: 00007ffcfc120ecf R14: 00007f55eb4779c0 R15: 000000000078c04c > Modules linked in: > ---[ end trace ea73d933d66ff0d4 ]--- > RIP: 0010:migration_entry_to_page include/linux/swapops.h:197 [inline] > RIP: 0010:migration_entry_to_page include/linux/swapops.h:190 [inline] > RIP: 0010:pmd_migration_entry_wait+0x493/0x520 mm/migrate.c:368 > Code: 4d 8d 66 ff e9 1f fe ff ff e8 b9 c4 be ff 49 8d 5f ff e9 58 fe ff ff e8 ab c4 be ff 4d 8d 66 ff e9 a9 fe ff ff e8 9d c4 be ff <0f> 0b e8 96 c4 be ff 0f 0b e8 8f c4 be ff 4c 8d 65 ff eb a7 48 89 > RSP: 0018:ffffc9001095fb70 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81b56a24 > RDX: ffff888092022240 RSI: ffffffff81b56b43 RDI: 0000000000000001 > RBP: ffffea0008468080 R08: 0000000000000000 R09: ffffea0008468087 > R10: 0000000000000000 R11: 0000000000000000 R12: ffffea0008468080 > R13: ffff888015d2e0c0 R14: 0000000000000000 R15: 0000000000000000 > FS: 00007f55eb477700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000020000080 CR3: 000000021ad87000 CR4: 00000000001526e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 >