INFO: task systemd-udevd:2973 blocked for more than 143 seconds. Not tainted 5.15.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-udevd state:D stack:22616 pid: 2973 ppid: 1 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 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: 0033:0x7f77516e3270 RSP: 002b:00007ffc3d24ef28 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007ffc3d24efc0 RCX: 00007f77516e3270 RDX: 0000000000000000 RSI: 000000000000125f RDI: 000000000000000e RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000010 R10: 00005573a6190480 R11: 0000000000000246 R12: 00007ffc3d24f0d0 R13: 00005573a6181010 R14: 00005573a6182170 R15: 00007ffc3d24efa0 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b983b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 2 locks held by systemd-udevd/2973: #0: ffff88801a588118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801a4e3b60 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:1748 1 lock held by in:imklog/6223: #0: ffff88801e826ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.2/14278: #0: ffff88801a588118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 1 lock held by syz-executor.2/14335: #0: ffff88801a588118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14 Comm: rcu_preempt Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0xc/0x70 kernel/kcov.c:293 Code: 4c 38 f0 48 c7 44 38 e0 05 00 00 00 48 89 74 38 e8 4e 89 54 c8 20 48 89 10 c3 0f 1f 40 00 49 89 f8 bf 03 00 00 00 4c 8b 14 24 <48> 89 f1 65 48 8b 34 25 40 70 02 00 e8 a3 f8 ff ff 84 c0 74 48 48 RSP: 0018:ffffc90000d37b38 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffc90000d37cc0 RCX: 0000000000000000 RDX: 1ffff1101738505a RSI: 0000000000000001 RDI: 0000000000000003 RBP: ffff8880b9c28280 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8166cf7c R11: 0000000000000000 R12: 0000000000000001 R13: 00000001000038e9 R14: 000000000a400000 R15: ffffc90000d37ce0 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c79aa8c920 CR3: 000000000b68e000 CR4: 0000000000350ef0 Call Trace: enqueue_timer+0x1dc/0x5c0 kernel/time/timer.c:593 internal_add_timer kernel/time/timer.c:611 [inline] __mod_timer+0x825/0xe30 kernel/time/timer.c:1062 schedule_timeout+0x145/0x2a0 kernel/time/timer.c:1880 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 4c 38 f0 rex.WR cmp %r14b,%al 3: 48 c7 44 38 e0 05 00 movq $0x5,-0x20(%rax,%rdi,1) a: 00 00 c: 48 89 74 38 e8 mov %rsi,-0x18(%rax,%rdi,1) 11: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) 16: 48 89 10 mov %rdx,(%rax) 19: c3 retq 1a: 0f 1f 40 00 nopl 0x0(%rax) 1e: 49 89 f8 mov %rdi,%r8 21: bf 03 00 00 00 mov $0x3,%edi 26: 4c 8b 14 24 mov (%rsp),%r10 * 2a: 48 89 f1 mov %rsi,%rcx <-- trapping instruction 2d: 65 48 8b 34 25 40 70 mov %gs:0x27040,%rsi 34: 02 00 36: e8 a3 f8 ff ff callq 0xfffff8de 3b: 84 c0 test %al,%al 3d: 74 48 je 0x87 3f: 48 rex.W