INFO: task systemd-udevd:4895 blocked for more than 143 seconds. Not tainted 5.10.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:systemd-udevd state:D stack:23208 pid: 4895 ppid: 1 flags:0x00004100 Call Trace: context_switch kernel/sched/core.c:3779 [inline] __schedule+0x893/0x2130 kernel/sched/core.c:4528 schedule+0xcf/0x270 kernel/sched/core.c:4606 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4665 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 __blkdev_get+0x457/0x1870 fs/block_dev.c:1479 blkdev_get+0xd1/0x240 fs/block_dev.c:1634 blkdev_open+0x21d/0x2b0 fs/block_dev.c:1751 do_dentry_open+0x4b9/0x11b0 fs/open.c:817 do_open fs/namei.c:3252 [inline] path_openat+0x1b9a/0x2730 fs/namei.c:3369 do_filp_open+0x17e/0x3c0 fs/namei.c:3396 do_sys_openat2+0x16d/0x420 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_sys_open fs/open.c:1192 [inline] __se_sys_open fs/open.c:1188 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1188 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fd822c04840 RSP: 002b:00007ffe33081818 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffe33081910 RCX: 00007fd822c04840 RDX: 0000556734698fe3 RSI: 00000000000a0800 RDI: 0000556734c97ad0 RBP: 00007ffe33081e00 R08: 0000556734698670 R09: 0000000000000010 R10: 000055673541dd40 R11: 0000000000000246 R12: 00007ffe330819c0 R13: 0000556734be3010 R14: 0000556735127f00 R15: 00007ffe33081890 Showing all locks held in the system: 1 lock held by khungtaskd/1656: #0: ffffffff8b3378e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by systemd-udevd/4895: #0: ffff888148012100 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x457/0x1870 fs/block_dev.c:1479 1 lock held by in:imklog/8162: #0: ffff88801abf14f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 2 locks held by syz-executor.3/32016: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1656 Comm: khungtaskd Not tainted 5.10.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 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:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4884 Comm: systemd-journal Not tainted 5.10.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:desc_read_finalized_seq+0x15b/0x1c0 kernel/printk/printk_ringbuffer.c:1779 Code: fc ff df 49 c7 04 04 00 00 00 00 48 8b 44 24 58 65 48 2b 04 25 28 00 00 00 75 63 48 83 c4 60 44 89 e8 5b 5d 41 5c 41 5d 41 5e <41> 5f c3 e8 6d 32 17 00 48 8d 7d 10 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc9000167fb78 EFLAGS: 00000086 RAX: 00000000fffffffe RBX: ffffc9000167fc50 RCX: ffffffff8158d187 RDX: ffff88802553cec0 RSI: ffffffff8158d1ca RDI: 0000000000000005 RBP: ffffffff8b312ab8 R08: 0000000000000001 R09: ffffc9000167fc57 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000001159 R13: ffffffff8b248a40 R14: 0000000000003159 R15: dffffc0000000000 FS: 00007f6b54d6c8c0(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b50fefb78 CR3: 00000000204da000 CR4: 0000000000350ee0 Call Trace: prb_read kernel/printk/printk_ringbuffer.c:1802 [inline] _prb_read_valid+0x1a1/0x6d0 kernel/printk/printk_ringbuffer.c:1882 prb_first_valid_seq+0x78/0xd0 kernel/printk/printk_ringbuffer.c:1987 devkmsg_read+0x274/0x740 kernel/printk/printk.c:785 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f6b542fc210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007ffd5820e6c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffd58211140 RCX: 00007f6b542fc210 RDX: 0000000000002000 RSI: 00007ffd5820ef40 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007ffd582d90f0 R10: 00000000000973e4 R11: 0000000000000246 R12: 00007ffd5820ef40 R13: 00007ffd58211098 R14: 000055b44cfbf958 R15: 0005b6314e1794e7