INFO: task syz-executor.0:2988 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23816 pid: 2988 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1761 blkdev_put_whole block/bdev.c:694 [inline] blkdev_put+0x2fb/0x9e0 block/bdev.c:956 deactivate_locked_super+0x94/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1137 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:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7ff19fd80f57 RSP: 002b:00007ffd02e77a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff19fd80f57 RDX: 00007ffd02e77b5a RSI: 000000000000000a RDI: 00007ffd02e77b50 RBP: 00007ffd02e77b50 R08: 00000000ffffffff R09: 00007ffd02e77920 R10: 0000555556e7a903 R11: 0000000000000246 R12: 00007ff19fdd9105 R13: 00007ffd02e78c10 R14: 0000555556e7a810 R15: 00007ffd02e78c50 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb80fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6219: #0: ffff88801ce8bbb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 4 locks held by kworker/u4:15/32752: 2 locks held by syz-executor.0/2988: #0: ffff88801ad3c118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801ac74360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2968 Comm: systemd-journal Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__this_cpu_preempt_check+0x1/0x20 lib/smp_processor_id.c:65 Code: b5 d6 cc ff eb a2 0f 1f 00 0f 1f 44 00 00 48 c7 c6 20 91 04 8a 48 c7 c7 60 91 04 8a e9 78 fe ff ff 0f 1f 84 00 00 00 00 00 55 <48> 89 fd 0f 1f 44 00 00 48 89 ee 5d 48 c7 c7 a0 91 04 8a e9 57 fe RSP: 0018:ffffc90001ae7a80 EFLAGS: 00000046 RAX: 0000000080000000 RBX: ffffffff81cb3c1d RCX: 0000000000000001 RDX: ffff888018e1e0c0 RSI: ffffffff817d11f9 RDI: ffffffff89abf720 RBP: ffffc90001ae7b40 R08: 0000000000000000 R09: 000000000000002f R10: ffffffff81cb39a9 R11: 000000000000002f R12: 0000000000000200 R13: 0000000000000000 R14: ffff888018faea00 R15: 0000000000000000 FS: 00007f98bda3b8c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f98bb1d4000 CR3: 000000007f748000 CR4: 00000000003506e0 DR0: 00000000000043ce DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_off+0x76/0xd0 kernel/locking/lockdep.c:4377 trace_hardirqs_off+0x13/0x1b0 kernel/trace/trace_preemptirq.c:76 seqcount_lockdep_reader_access include/linux/seqlock.h:102 [inline] set_root+0x39d/0x5b0 fs/namei.c:940 nd_jump_root+0x3c8/0x570 fs/namei.c:961 path_init+0x1020/0x1920 fs/namei.c:2359 path_lookupat+0x30/0x860 fs/namei.c:2439 filename_lookup+0x1c6/0x590 fs/namei.c:2478 user_path_at_empty+0x42/0x60 fs/namei.c:2801 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x127/0x850 fs/open.c:421 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+0x44/0xae RIP: 0033:0x7f98bccf69c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffff7ba3938 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffff7ba6960 RCX: 00007f98bccf69c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055c078eb19a3 RBP: 00007ffff7ba3a80 R08: 000055c078ea73e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055c079e408c0 R15: 00007ffff7ba3f70 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: eb a2 jmp 0xffffffa4 2: 0f 1f 00 nopl (%rax) 5: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) a: 48 c7 c6 20 91 04 8a mov $0xffffffff8a049120,%rsi 11: 48 c7 c7 60 91 04 8a mov $0xffffffff8a049160,%rdi 18: e9 78 fe ff ff jmpq 0xfffffe95 1d: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 24: 00 25: 55 push %rbp * 26: 48 89 fd mov %rdi,%rbp <-- trapping instruction 29: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 2e: 48 89 ee mov %rbp,%rsi 31: 5d pop %rbp 32: 48 c7 c7 a0 91 04 8a mov $0xffffffff8a0491a0,%rdi 39: e9 .byte 0xe9 3a: 57 push %rdi 3b: fe .byte 0xfe