From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com ([209.85.214.71]:44102 "EHLO mail-it0-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727034AbeGPAns (ORCPT ); Sun, 15 Jul 2018 20:43:48 -0400 Received: by mail-it0-f71.google.com with SMTP id z8-v6so12665555itc.9 for ; Sun, 15 Jul 2018 17:19:03 -0700 (PDT) MIME-Version: 1.0 Date: Sun, 15 Jul 2018 17:19:03 -0700 Message-ID: <000000000000dcb1a1057112c66a@google.com> Subject: kernel BUG at fs/userfaultfd.c:LINE! (2) From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hello, syzbot found the following crash on: HEAD commit: 37b5dca2898d Merge tag 'rtc-4.18-2' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12aaf3b2400000 kernel config: https://syzkaller.appspot.com/x/.config?x=25856fac4e580aa7 dashboard link: https://syzkaller.appspot.com/bug?extid=121be635a7a35ddb7dcb compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=11176d62400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1362b368400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+121be635a7a35ddb7dcb@syzkaller.appspotmail.com random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ------------[ cut here ]------------ kernel BUG at fs/userfaultfd.c:883! invalid opcode: 0000 [#1] SMP KASAN CPU: 0 PID: 4708 Comm: syz-executor086 Not tainted 4.18.0-rc4+ #148 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:userfaultfd_release+0x5fb/0x770 fs/userfaultfd.c:882 Code: 00 31 c0 48 8b 4d d0 65 48 33 0c 25 28 00 00 00 0f 85 a1 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 be a0 ff <0f> 0b 4c 89 f7 e8 0b 9e de ff e9 11 fc ff ff 4c 89 e7 e8 5e 9d de RSP: 0018:ffff8801d8407a80 EFLAGS: 00010293 RAX: ffff8801d8742080 RBX: dffffc0000000000 RCX: ffffffff81db4a59 RDX: 0000000000000000 RSI: ffffffff81db4ccb RDI: 0000000000000000 RBP: ffff8801d8407bd0 R08: ffff8801d8742080 R09: 0000000000000000 R10: ffff8801d87428b8 R11: 16fb0df9f74494d6 R12: ffff8801d89a3b58 R13: 0000000000000000 R14: ffff8801d89a3a50 R15: 0000000000000000 FS: 0000000000ed6880(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f45c6b81e78 CR3: 00000001acb61000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __fput+0x355/0x8b0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:192 [inline] exit_to_usermode_loop+0x313/0x370 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x405471 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 54 17 00 00 c3 48 83 ec 08 e8 6a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 b3 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffcad3db600 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000405471 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffcad3db610 R11: 0000000000000293 R12: 00000000006dbc3c R13: 00000000006dbda0 R14: 0000000000000008 R15: 0000000000000001 Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 638e68cedadb8eda ]--- RIP: 0010:userfaultfd_release+0x5fb/0x770 fs/userfaultfd.c:882 Code: 00 31 c0 48 8b 4d d0 65 48 33 0c 25 28 00 00 00 0f 85 a1 00 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 be a0 ff <0f> 0b 4c 89 f7 e8 0b 9e de ff e9 11 fc ff ff 4c 89 e7 e8 5e 9d de RSP: 0018:ffff8801d8407a80 EFLAGS: 00010293 RAX: ffff8801d8742080 RBX: dffffc0000000000 RCX: ffffffff81db4a59 RDX: 0000000000000000 RSI: ffffffff81db4ccb RDI: 0000000000000000 RBP: ffff8801d8407bd0 R08: ffff8801d8742080 R09: 0000000000000000 R10: ffff8801d87428b8 R11: 16fb0df9f74494d6 R12: ffff8801d89a3b58 R13: 0000000000000000 R14: ffff8801d89a3a50 R15: 0000000000000000 FS: 0000000000ed6880(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f45c6b81e78 CR3: 00000001acb61000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 --- This bug is generated by a bot. 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