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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 211D4C2D0E4 for ; Tue, 24 Nov 2020 03:42:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 56F9D20866 for ; Tue, 24 Nov 2020 03:42:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="dSncuCME" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 56F9D20866 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 629CE6B005D; Mon, 23 Nov 2020 22:42:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5DB396B006E; Mon, 23 Nov 2020 22:42:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 51A966B0070; Mon, 23 Nov 2020 22:42:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0040.hostedemail.com [216.40.44.40]) by kanga.kvack.org (Postfix) with ESMTP id 2469E6B005D for ; Mon, 23 Nov 2020 22:42:34 -0500 (EST) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C51E0180AD811 for ; Tue, 24 Nov 2020 03:42:33 +0000 (UTC) X-FDA: 77517914586.24.pie83_601596f2736a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin24.hostedemail.com (Postfix) with ESMTP id A6C5D1A4A0 for ; Tue, 24 Nov 2020 03:42:33 +0000 (UTC) X-HE-Tag: pie83_601596f2736a X-Filterd-Recvd-Size: 7096 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Tue, 24 Nov 2020 03:42:32 +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 7445020857; Tue, 24 Nov 2020 03:42:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1606189351; bh=NOfCsv/YXXhVyGt2Kvus7SwHhbMMgHytZAwpTGpbP1A=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=dSncuCME1df9nPGIAKe1Il9qlXmqUITCmBKzTnQLqfTyT/o97OW4p4jsVfzZSxRSt Itzg6RGRFfb6MDkUofsiWFRomKRHd7h8B/d8DAEj3N6umKgyFXza4sgZeHpVUjp0F9 LWccMbCvLeVwt+KeUXTYTlpdCwPEmsV/fVeQRQQk= Date: Mon, 23 Nov 2020 19:42:30 -0800 From: Andrew Morton To: syzbot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, Thomas Gleixner , Matthew Wilcox Subject: Re: kernel BUG at include/linux/highmem.h:LINE! Message-Id: <20201123194230.f59c93eba3cf356c632eb1c0@linux-foundation.org> In-Reply-To: <000000000000f6914405b49d9c9d@google.com> References: <000000000000f6914405b49d9c9d@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-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 Sat, 21 Nov 2020 05:05:19 -0800 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 7c8ca812 Add linux-next specific files for 20201117 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=16ea946a500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ff4bc71371dc5b13 > dashboard link: https://syzkaller.appspot.com/bug?extid=dcb847a3e1e0ecd191ab > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14530c7a500000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=137c581c500000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+dcb847a3e1e0ecd191ab@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > kernel BUG at include/linux/highmem.h:202! Thomas has changed the highmem code (well, kmap) quite a bit. But I don't think that's the culprit here. > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 8526 Comm: syz-executor603 Not tainted 5.10.0-rc4-next-20201117-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:zero_user_segments include/linux/highmem.h:202 [inline] > RIP: 0010:zero_user include/linux/highmem.h:223 [inline] > RIP: 0010:truncate_inode_partial_page+0x5aa/0x720 mm/truncate.c:264 > Code: bc 01 00 00 00 e8 e6 f8 ff ff e9 e7 fe ff ff e8 2c 12 d8 ff 48 c7 c6 00 44 54 89 48 89 ef e8 dd b5 08 00 0f 0b e8 16 12 d8 ff <0f> 0b e8 0f 12 d8 ff 48 c7 c6 80 44 54 89 48 89 ef e8 c0 b5 08 00 > RSP: 0018:ffffc90000f8fa00 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000000200000 RCX: ffffffff81987fe1 > RDX: ffff88801e614f80 RSI: ffffffff819882ca RDI: 0000000000000005 > RBP: ffffea0000c70000 R08: 0000000000000000 R09: ffffea0000c70007 > R10: 0000000000001000 R11: 0000000000000000 R12: 00000000001ffffa > R13: 00000000001ffffa R14: 0000000000000006 R15: ffffea0000c70008 > FS: 0000000000e30880(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000043e920 CR3: 00000000228a7000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > shmem_undo_range+0x6fd/0x18f0 mm/shmem.c:921 > shmem_truncate_range mm/shmem.c:999 [inline] > shmem_setattr+0x67a/0xc70 mm/shmem.c:1058 > notify_change+0xb60/0x10a0 fs/attr.c:336 > do_truncate+0x134/0x1f0 fs/open.c:64 > vfs_truncate+0x49e/0x600 fs/open.c:110 > do_sys_truncate.part.0+0x11e/0x140 fs/open.c:133 > do_sys_truncate fs/open.c:127 [inline] > __do_sys_truncate fs/open.c:145 [inline] > __se_sys_truncate fs/open.c:143 [inline] > __x64_sys_truncate+0x69/0x90 fs/open.c:143 > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 Matthew's series "Overhaul multi-page lookups for THP" chnages the shmem code quite a bit, and in the area of truncate. Matthew, could you please fire up that reproducer? > RIP: 0033:0x444109 > Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db d7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007ffec4a90088 EFLAGS: 00000246 ORIG_RAX: 000000000000004c > RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444109 > RDX: 0000000000444109 RSI: 0000000000000006 RDI: 0000000020000040 > RBP: 00000000006ce018 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000401d70 > R13: 0000000000401e00 R14: 0000000000000000 R15: 0000000000000000 > Modules linked in: > ---[ end trace 910e59f95b39ab18 ]--- > RIP: 0010:zero_user_segments include/linux/highmem.h:202 [inline] > RIP: 0010:zero_user include/linux/highmem.h:223 [inline] > RIP: 0010:truncate_inode_partial_page+0x5aa/0x720 mm/truncate.c:264 > Code: bc 01 00 00 00 e8 e6 f8 ff ff e9 e7 fe ff ff e8 2c 12 d8 ff 48 c7 c6 00 44 54 89 48 89 ef e8 dd b5 08 00 0f 0b e8 16 12 d8 ff <0f> 0b e8 0f 12 d8 ff 48 c7 c6 80 44 54 89 48 89 ef e8 c0 b5 08 00 > RSP: 0018:ffffc90000f8fa00 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000000200000 RCX: ffffffff81987fe1 > RDX: ffff88801e614f80 RSI: ffffffff819882ca RDI: 0000000000000005 > RBP: ffffea0000c70000 R08: 0000000000000000 R09: ffffea0000c70007 > R10: 0000000000001000 R11: 0000000000000000 R12: 00000000001ffffa > R13: 00000000001ffffa R14: 0000000000000006 R15: ffffea0000c70008 > FS: 0000000000e30880(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000043e920 CR3: 00000000228a7000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this issue, for details see: > https://goo.gl/tpsmEJ#testing-patches