INFO: task systemd-udevd:8679 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:systemd-udevd state:D stack:27096 pid: 8679 ppid: 2969 flags:0x00004000 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 lo_release+0x160/0x1f0 drivers/block/loop.c:1768 blkdev_put_whole block/bdev.c:694 [inline] blkdev_put+0x2fb/0x9e0 block/bdev.c:956 blkdev_close+0x6a/0x80 block/fops.c:515 __fput+0x286/0x9f0 fs/file_table.c:280 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: 0033:0x7f22a7469270 RSP: 002b:00007fffd27eadc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f22a7469270 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007f22a8323710 R08: 000055749dbfead0 R09: 000055749dc0e700 R10: 00007f22a83238c0 R11: 0000000000000246 R12: 0000000000000000 R13: 000055749dc0ce10 R14: 0000000000000003 R15: 000000000000000e Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6215: #0: ffff88807df3b770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by systemd-udevd/8679: #0: ffff88801a8c2118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801a5ddb60 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:1748 5 locks held by kworker/u4:13/8963: 1 lock held by syz-executor.2/9552: #0: ffff88801a8c2118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x24e/0xb50 block/bdev.c:819 ============================================= 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:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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: 7441 Comm: kworker/u4:6 Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__default_send_IPI_dest_field+0x7c/0x130 arch/x86/kernel/apic/ipi.c:173 Code: 00 c3 5f ff f6 c4 10 75 e2 44 89 e7 c1 e7 18 89 3c 25 10 c3 5f ff 89 f0 09 d8 80 cf 04 83 fe 02 0f 44 c3 89 04 25 00 c3 5f ff <48> 83 c4 08 5b 5d 41 5c c3 48 c7 c0 60 4a 56 8b 48 ba 00 00 00 00 RSP: 0018:ffffc9000588f9b0 EFLAGS: 00000006 RAX: 00000000000008fb RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000800 RSI: 00000000000000fb RDI: 0000000001000000 RBP: fffffbffffebf860 R08: 0000000000000000 R09: ffff8880b9d3ab97 R10: ffffffff817e26bd R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efe3c4d5020 CR3: 000000000b88e000 CR4: 0000000000350ee0 Call Trace: _flat_send_IPI_mask+0x4e/0x60 arch/x86/kernel/apic/apic_flat_64.c:56 smp_call_function_many_cond+0xa33/0xc20 kernel/smp.c:949 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1112 [inline] text_poke_bp_batch+0x47d/0x560 arch/x86/kernel/alternative.c:1366 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline] text_poke_flush arch/x86/kernel/alternative.c:1448 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_disable_cpuslocked+0x152/0x1b0 kernel/jump_label.c:207 static_key_disable+0x16/0x20 kernel/jump_label.c:215 toggle_allocation_gate mm/kfence/core.c:746 [inline] toggle_allocation_gate+0x183/0x390 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), 4 bytes skipped: 0: f6 c4 10 test $0x10,%ah 3: 75 e2 jne 0xffffffe7 5: 44 89 e7 mov %r12d,%edi 8: c1 e7 18 shl $0x18,%edi b: 89 3c 25 10 c3 5f ff mov %edi,0xffffffffff5fc310 12: 89 f0 mov %esi,%eax 14: 09 d8 or %ebx,%eax 16: 80 cf 04 or $0x4,%bh 19: 83 fe 02 cmp $0x2,%esi 1c: 0f 44 c3 cmove %ebx,%eax 1f: 89 04 25 00 c3 5f ff mov %eax,0xffffffffff5fc300 * 26: 48 83 c4 08 add $0x8,%rsp <-- trapping instruction 2a: 5b pop %rbx 2b: 5d pop %rbp 2c: 41 5c pop %r12 2e: c3 retq 2f: 48 c7 c0 60 4a 56 8b mov $0xffffffff8b564a60,%rax 36: 48 rex.W 37: ba 00 00 00 00 mov $0x0,%edx