INFO: task systemd-udevd:24800 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:26928 pid:24800 ppid: 2973 flags:0x00000000 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6382 __mutex_lock_common kernel/locking/mutex.c:680 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 lo_release+0x4d/0x1f0 drivers/block/loop.c:1748 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: 0033:0x7ff0922c8270 RSP: 002b:00007ffc5275a878 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007ff0922c8270 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007ff093182710 R08: 0000564e1c92d0b0 R09: 0000564e1c92ce00 R10: 00007ff0931828c0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000564e1c9289f0 R14: 0000000000000003 R15: 000000000000000e INFO: task syz-executor.4:24879 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:syz-executor.4 state:D stack:28480 pid:24879 ppid: 7069 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 loop_set_status+0x17d/0x930 drivers/block/loop.c:1264 loop_set_status_old+0x148/0x1b0 drivers/block/loop.c:1396 lo_ioctl+0x3e9/0x17c0 drivers/block/loop.c:1566 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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: 0033:0x7f94cd1bcae9 RSP: 002b:00007f94ca6cf188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f94cd2d01a0 RCX: 00007f94cd1bcae9 RDX: 0000000020000780 RSI: 0000000000004c02 RDI: 0000000000000003 RBP: 00007f94cd216f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f94cd803b2f R14: 00007f94ca6cf300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6234: 2 locks held by systemd-udevd/24800: #0: ffff88801a4c7918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x97/0x9e0 block/bdev.c:914 #1: ffff88801a4c3360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:1748 1 lock held by syz-executor.4/24879: #0: ffff88801a4c3360 (&lo->lo_mutex){+.+.}-{3:3}, at: loop_set_status+0x2a/0x930 drivers/block/loop.c:1248 ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2951 Comm: systemd-journal Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0033:0x7fd1b5fe577b Code: 41 5d 41 5e 41 5f c3 0f 1f 84 00 00 00 00 00 41 8b 77 08 41 8b 57 04 31 c0 49 8b 7f 28 81 ce 00 00 08 00 e8 47 83 fe ff 85 c0 <41> 89 07 78 30 41 80 4f 10 20 e9 bc fb ff ff 66 0f 1f 44 00 00 41 RSP: 002b:00007ffde2ceebd0 EFLAGS: 00000286 RAX: ffffffffffffffff RBX: 00007ffde2ceeed0 RCX: fffffffffffffe00 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055c5c90800f0 RBP: 000000000000000d R08: 00000000000001e0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 000055c5c9072040 R14: 00007ffde2ceee90 R15: 000055c5c907ff10 FS: 00007fd1b63c78c0 GS: 0000000000000000