INFO: task kworker/u4:2:50 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:kworker/u4:2 state:D
stack:24456 pid: 50 ppid: 2 flags:0x00004000
Workqueue: nbd-del nbd_dev_remove_work
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
del_gendisk+0x598/0x860 block/genhd.c:623
nbd_dev_remove+0x3c/0xf0 drivers/block/nbd.c:252
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
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
2 locks held by kworker/u4:2/50:
#0: ffff88801ac69138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff88801ac69138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff88801ac69138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff88801ac69138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff88801ac69138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff88801ac69138 ((wq_completion)nbd-del){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc9000119fdb0 ((work_completion)(&nbd->remove_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
1 lock held by systemd-udevd/2973:
1 lock held by in:imklog/6427:
#0: ffff88807db9cd70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
2 locks held by agetty/6443:
#0: ffff88807e420098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252
#1: ffffc90002adc2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113
1 lock held by syz-executor.5/6553:
5 locks held by kworker/0:4/7958:
#0: ffff888011d89d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888011d89d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888011d89d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff888011d89d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff888011d89d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff888011d89d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc90016e0fdb0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
#2: ffff888147b56220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#2: ffff888147b56220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4330 drivers/usb/core/hub.c:5662
#3: ffff88802bd40220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#3: ffff88802bd40220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:944
#4: ffff888018e3d468 (hcd->bandwidth_mutex){+.+.}-{3:3}, at: usb_set_configuration+0x61f/0x1900 drivers/usb/core/message.c:2038
1 lock held by syz-executor.4/17498:
3 locks held by syz-executor.3/27679:
=============================================
NMI backtrace for cpu 1
CPU: 1 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: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: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: 27679 Comm: syz-executor.3 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:delay_tsc+0x2e/0xb0 arch/x86/lib/delay.c:79
Code: fd bf 01 00 00 00 41 54 55 53 e8 ad 9f 4d fd e8 e8 7f 41 05 41 89 c4 0f 01 f9 66 90 48 c1 e2 20 48 09 c2 48 89 d5 eb 16 f3 90 01 00 00 00 e8 88 9f 4d fd e8 c3 7f 41 05 44 39 e0 75 36 0f 01
RSP: 0018:ffffc90004fef8b8 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 0000015b53f65925 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000015b53d732be R08: 0000000000000000 R09: ffff8880185701cf
R10: ffffffff841a42a1 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000225522 R14: dffffc0000000000 R15: 00000000000003c0
FS: 00007f2d9ac0e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9cdb5a3718 CR3: 000000002ff3e000 CR4: 0000000000350ef0
Call Trace:
vga16fb_set_par+0x753/0xc00 drivers/video/fbdev/vga16fb.c:625
fb_set_var+0x602/0xe70 drivers/video/fbdev/core/fbmem.c:1036
do_fb_ioctl+0x2f9/0x690 drivers/video/fbdev/core/fbmem.c:1112
fb_ioctl+0xe7/0x150 drivers/video/fbdev/core/fbmem.c:1189
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: 0033:0x7f2d9d698ae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2d9ac0e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2d9d7abf60 RCX: 00007f2d9d698ae9
RDX: 00000000200001c0 RSI: 0000000000004601 RDI: 0000000000000004
RBP: 00007f2d9d6f2f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdd6b377af R14: 00007f2d9ac0e300 R15: 0000000000022000
----------------
Code disassembly (best guess):
0: fd std
1: bf 01 00 00 00 mov $0x1,%edi
6: 41 54 push %r12
8: 55 push %rbp
9: 53 push %rbx
a: e8 ad 9f 4d fd callq 0xfd4d9fbc
f: e8 e8 7f 41 05 callq 0x5417ffc
14: 41 89 c4 mov %eax,%r12d
17: 0f 01 f9 rdtscp
1a: 66 90 xchg %ax,%ax
1c: 48 c1 e2 20 shl $0x20,%rdx
20: 48 09 c2 or %rax,%rdx
23: 48 89 d5 mov %rdx,%rbp
26: eb 16 jmp 0x3e
28: f3 90 pause
* 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction
2f: e8 88 9f 4d fd callq 0xfd4d9fbc
34: e8 c3 7f 41 05 callq 0x5417ffc
39: 44 39 e0 cmp %r12d,%eax
3c: 75 36 jne 0x74
3e: 0f .byte 0xf
3f: 01 .byte 0x1