------------[ cut here ]------------ WARNING: CPU: 0 PID: 8477 at fs/btrfs/volumes.c:1168 close_fs_devices+0x772/0x9a0 fs/btrfs/volumes.c:1168 Modules linked in: CPU: 0 PID: 8477 Comm: syz-executor.2 Tainted: G W 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:close_fs_devices+0x772/0x9a0 fs/btrfs/volumes.c:1168 Code: e8 93 d0 2f fe 85 db 0f 85 07 f9 ff ff e8 46 c9 2f fe 0f 0b e9 fb f8 ff ff e8 3a c9 2f fe 0f 0b e9 e2 fd ff ff e8 2e c9 2f fe <0f> 0b e9 19 fe ff ff 48 c7 c7 ec 7c 6c 8d e8 8b e9 75 fe e9 bb f8 RSP: 0018:ffffc900016efbd0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff888022c254c0 RSI: ffffffff8345bf82 RDI: 0000000000000003 RBP: dffffc0000000000 R08: 0000000000000000 R09: ffff88802d6be93b R10: ffffffff8345bd99 R11: 0000000000000000 R12: ffff88802d6be938 R13: 0000000000000000 R14: ffff888032a32108 R15: ffff88802d6be850 FS: 000000000174e400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a0b166dee0 CR3: 000000006ca42000 CR4: 0000000000350ef0 Call Trace: btrfs_close_devices+0x8e/0x4b0 fs/btrfs/volumes.c:1180 close_ctree+0x752/0x795 fs/btrfs/disk-io.c:4433 generic_shutdown_super+0x14c/0x370 fs/super.c:465 kill_anon_super+0x36/0x60 fs/super.c:1057 btrfs_kill_super+0x38/0x50 fs/btrfs/super.c:2367 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: 0033:0x467a37 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:00007ffd7313b308 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a37 RDX: 00007ffd7313b3dc RSI: 0000000000000002 RDI: 00007ffd7313b3d0 RBP: 00007ffd7313b3d0 R08: 00000000ffffffff R09: 00007ffd7313b1a0 R10: 000000000174f8e3 R11: 0000000000000246 R12: 00000000004bee70 R13: 00007ffd7313c4a0 R14: 000000000174f810 R15: 00007ffd7313c4e0