INFO: task syz-executor.0:6548 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:22112 pid: 6548 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 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: 0033:0x7fab1132af57 RSP: 002b:00007fffbace7db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fab1132af57 RDX: 00007fffbace7e8a RSI: 000000000000000a RDI: 00007fffbace7e80 RBP: 00007fffbace7e80 R08: 00000000ffffffff R09: 00007fffbace7c50 R10: 00005555557ed903 R11: 0000000000000246 R12: 00007fab11383105 R13: 00007fffbace8f40 R14: 00005555557ed810 R15: 00007fffbace8f80 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 2 locks held by kworker/u4:3/90: #0: ffff8880b9c39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #1: ffff8880b9c279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x173/0x490 kernel/sched/psi.c:871 1 lock held by in:imklog/6289: #0: ffff88806ff32ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by rs:main Q:Reg/6290: #0: ffff8880b9c39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 #1: ffff8880b9c279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a6/0x490 kernel/sched/psi.c:880 #2: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: trace_sched_stat_runtime include/trace/events/sched.h:517 [inline] #2: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: update_curr+0x370/0x900 kernel/sched/fair.c:876 2 locks held by syz-executor.0/6548: #0: ffff88801a434118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff8881473f6b60 (&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-next-20211118-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:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 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: 1319 Comm: kworker/u4:5 Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:lock_acquire+0xc/0x510 kernel/locking/lockdep.c:5605 Code: e9 b7 fe ff ff 48 c7 c7 08 1c 91 8d e8 8d b3 61 00 e9 fb fe ff ff 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 <41> 89 f7 41 56 49 89 fe 41 55 41 89 d5 41 54 41 89 cc 55 44 89 c5 RSP: 0018:ffffc9000598f9a0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffc90005988000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b9d39a98 RBP: ffff8880b9d39a80 R08: 0000000000000001 R09: 0000000000000000 R10: fffffbfff1b21cfa R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880b9d39a80 R14: ffff88801cf2d600 R15: ffff888010c69800 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb4f272000 CR3: 000000000b88e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x2b/0x120 kernel/sched/core.c:478 raw_spin_rq_lock kernel/sched/sched.h:1318 [inline] rq_lock kernel/sched/sched.h:1616 [inline] __schedule+0x242/0x4940 kernel/sched/core.c:6182 schedule+0xd2/0x260 kernel/sched/core.c:6341 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 toggle_allocation_gate mm/kfence/core.c:739 [inline] toggle_allocation_gate+0x305/0x390 mm/kfence/core.c:724 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: e9 b7 fe ff ff jmpq 0xfffffebc 5: 48 c7 c7 08 1c 91 8d mov $0xffffffff8d911c08,%rdi c: e8 8d b3 61 00 callq 0x61b39e 11: e9 fb fe ff ff jmpq 0xffffff11 16: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 1d: 00 1e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 25: fc ff df 28: 41 57 push %r15 * 2a: 41 89 f7 mov %esi,%r15d <-- trapping instruction 2d: 41 56 push %r14 2f: 49 89 fe mov %rdi,%r14 32: 41 55 push %r13 34: 41 89 d5 mov %edx,%r13d 37: 41 54 push %r12 39: 41 89 cc mov %ecx,%r12d 3c: 55 push %rbp 3d: 44 89 c5 mov %r8d,%ebp