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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD6E5C43334 for ; Mon, 13 Jun 2022 19:25:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350453AbiFMTZZ (ORCPT ); Mon, 13 Jun 2022 15:25:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350474AbiFMTZH (ORCPT ); Mon, 13 Jun 2022 15:25:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78AA83614E for ; Mon, 13 Jun 2022 10:41:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E84F860F71 for ; Mon, 13 Jun 2022 17:41:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F7E0C34114; Mon, 13 Jun 2022 17:41:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1655142089; bh=EhXZ8nwjvG7Is/AQKsJc4Np8BsZB+E9sA9nAWAwc81g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Vata14MZ1y1CEXhew/wz5vQ6tAhOTuM64dK67d4bxfkvLS7WXKFiOWhJUJ3nnL/Os lCOX3h53QRC79qTwRYrQyAHN9Th4W/4FOexMwfTn0EncBhpztxgOfNbkwH9uK0DcuV BgZj/uf/b834Jijd46OZQNHRkP+xTQnbvjaxlSg0= Date: Mon, 13 Jun 2022 10:41:28 -0700 From: Andrew Morton To: syzbot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, Axel Rasmussen , Peter Xu Subject: Re: [syzbot] kernel BUG in mcopy_continue Message-Id: <20220613104128.fc55ed6ab63c428e502bc483@linux-foundation.org> In-Reply-To: <00000000000039bfb905e14ea9d0@google.com> References: <00000000000039bfb905e14ea9d0@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 12 Jun 2022 23:47:26 -0700 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 6d0c80680317 Add linux-next specific files for 20220610 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=13a777f7f00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a30d6e3e814e5931 > dashboard link: https://syzkaller.appspot.com/bug?extid=3f1e5c1dea3a2e66ea9a > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+3f1e5c1dea3a2e66ea9a@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > kernel BUG at mm/userfaultfd.c:642! Thanks. I'm looking suspiciously at "mm: userfaultfd: fix UFFDIO_CONTINUE on fallocated shmem pages"? > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 14685 Comm: syz-executor.4 Not tainted 5.19.0-rc1-next-20220610-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:__mcopy_atomic mm/userfaultfd.c:642 [inline] > RIP: 0010:mcopy_continue+0x80f/0x1360 mm/userfaultfd.c:699 > Code: a8 ff 49 83 fd fe 0f 85 bd fd ff ff e8 ba ca a8 ff 0f 1f 44 00 00 e8 b0 ca a8 ff e8 ab ca a8 ff 48 8b 7c 24 20 e8 51 76 8b ff <0f> 0b e8 9a ca a8 ff 0f 0b e8 93 ca a8 ff 4d 89 ee 31 ff 41 81 e6 > RSP: 0018:ffffc900058f7b70 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: ffff8880226dee58 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88801a0b4228 > RBP: 0000000020531000 R08: 0000000000000001 R09: ffff88801a0b422f > R10: ffffed1003416845 R11: 0000000000000001 R12: 0000000000000000 > R13: fffffffffffffffe R14: 00000000fffffffe R15: ffff88801a0b4140 > FS: 00007f91409ee700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b2c522000 CR3: 000000001d578000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > userfaultfd_continue fs/userfaultfd.c:1893 [inline] > userfaultfd_ioctl+0x1818/0x41f0 fs/userfaultfd.c:2017 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:870 [inline] > __se_sys_ioctl fs/ioctl.c:856 [inline] > __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x46/0xb0 > RIP: 0033:0x7f913f889109 > Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007f91409ee168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007f913f99c030 RCX: 00007f913f889109 > RDX: 0000000020000040 RSI: 00000000c020aa07 RDI: 0000000000000004 > RBP: 00007f913f8e30ad R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffcb29c401f R14: 00007f91409ee300 R15: 0000000000022000 > > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:__mcopy_atomic mm/userfaultfd.c:642 [inline] > RIP: 0010:mcopy_continue+0x80f/0x1360 mm/userfaultfd.c:699 > Code: a8 ff 49 83 fd fe 0f 85 bd fd ff ff e8 ba ca a8 ff 0f 1f 44 00 00 e8 b0 ca a8 ff e8 ab ca a8 ff 48 8b 7c 24 20 e8 51 76 8b ff <0f> 0b e8 9a ca a8 ff 0f 0b e8 93 ca a8 ff 4d 89 ee 31 ff 41 81 e6 > RSP: 0018:ffffc900058f7b70 EFLAGS: 00010282 > RAX: 0000000000000000 RBX: ffff8880226dee58 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88801a0b4228 > RBP: 0000000020531000 R08: 0000000000000001 R09: ffff88801a0b422f > R10: ffffed1003416845 R11: 0000000000000001 R12: 0000000000000000 > R13: fffffffffffffffe R14: 00000000fffffffe R15: ffff88801a0b4140 > FS: 00007f91409ee700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f91409cd718 CR3: 000000001d578000 CR4: 00000000003526f0 > 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.