syzbot has found a reproducer for the following issue on: HEAD commit: 90d856e71443 Add linux-next specific files for 20210723 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=140c92b6300000 kernel config: https://syzkaller.appspot.com/x/.config?x=298516715f6ad5cd dashboard link: https://syzkaller.appspot.com/bug?extid=fcdd69a8426baab36109 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=146b2066300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fcdd69a8426baab36109@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ WARNING: CPU: 1 PID: 8499 at kernel/workqueue.c:4413 destroy_workqueue.cold+0x5/0x71 kernel/workqueue.c:4413 Modules linked in: CPU: 1 PID: 8499 Comm: syz-executor.5 Not tainted 5.14.0-rc2-next-20210723-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:destroy_workqueue.cold+0x5/0x71 kernel/workqueue.c:4413 Code: c5 3d 7a f8 b9 e8 03 00 00 31 d2 48 c7 c7 e0 ff 8a 89 f7 f1 89 c6 e8 fc 87 00 00 c6 44 24 2f 01 e9 e7 56 62 f8 e8 6f c4 8b f8 <0f> 0b 48 c7 c6 e0 04 8b 89 48 c7 c7 20 00 8b 89 49 8d 96 60 01 00 RSP: 0018:ffffc90001b3fcd0 EFLAGS: 00010093 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000 RDX: ffff88801bedd580 RSI: ffffffff88e9fd31 RDI: 0000000000000003 RBP: 000000000000000f R08: 0000000000000001 R09: 0000000000000003 R10: ffffffff814c5ab3 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffe8ffffd91a00 R14: ffff88802a9d2400 R15: 0000000000000000 FS: 000000000290e400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef18ce720 CR3: 00000000370a3000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: reiserfs_put_super+0x234/0x5c0 fs/reiserfs/super.c:631 generic_shutdown_super+0x14c/0x370 fs/super.c:465 kill_block_super+0x97/0xf0 fs/super.c:1395 deactivate_locked_super+0x94/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1136 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x467a47 Code: ff d0 48 89 c7 b8 3c 00 00 00 0f 05 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffca786e4d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a47 RDX: 00007ffca786e5a9 RSI: 0000000000000002 RDI: 00007ffca786e5a0 RBP: 00007ffca786e5a0 R08: 00000000ffffffff R09: 00007ffca786e370 R10: 000000000290f8e3 R11: 0000000000000246 R12: 00000000004bee90 R13: 00007ffca786f670 R14: 000000000290f810 R15: 00007ffca786f6b0
