INFO: task syz-executor.0:4595 blocked for more than 143 seconds.
Not tainted 5.15.189-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:27680 pid: 4595 ppid: 4508 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_timeout+0x97/0x280 kernel/time/timer.c:1890
do_wait_for_common+0x29a/0x440 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
flush_workqueue+0x63a/0x1380 kernel/workqueue.c:2882
nbd_start_device_ioctl drivers/block/nbd.c:1365 [inline]
__nbd_ioctl drivers/block/nbd.c:1427 [inline]
nbd_ioctl+0xaea/0xe40 drivers/block/nbd.c:1467
blkdev_ioctl+0x33c/0x690 block/ioctl.c:604
block_ioctl+0xac/0xf0 block/fops.c:496
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f78556fdae9
RSP: 002b:00007f7854a7f0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f785581cf80 RCX: 00007f78556fdae9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f785574947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f785581cf80 R15: 00007ffd98bc3928
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/u4:3/893:
#0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
#1: ffff8880b9027848 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4d6/0x810 kernel/sched/psi.c:891
1 lock held by klogd/3550:
#0: ffff8880b903a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
3 locks held by udevd/3561:
2 locks held by getty/3953:
#0: ffff88802bc6f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
2 locks held by kworker/u5:2/4197:
#0: ffff88802060b938 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002f5fd00 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
1 lock held by syz-executor.0/8471:
#0: ffff8880205f7a08 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x140/0xe40 drivers/block/nbd.c:1460
1 lock held by syz-executor.0/8472:
#0: ffff8880205f7a08 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x140/0xe40 drivers/block/nbd.c:1460
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8470 Comm: syz-executor.0 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:common_nsleep+0x0/0xa0 kernel/time/posix-timers.c:1270
Code: fd ff 31 c0 5b 41 5e c3 89 d9 80 e1 07 80 c1 03 38 c1 7c e5 49 89 fe 48 89 df e8 7b 65 52 00 4c 89 f7 eb d5 66 0f 1f 44 00 00 <55> 41 57 41 56 41 54 53 49 89 d6 89 f5 89 fb 49 bc 00 00 00 00 00
RSP: 0018:ffffc9000c53fe58 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff888022574128 RCX: dffffc0000000000
RDX: ffffc9000c53fea0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000c53ff10 R08: 00000000000f4240 R09: fffff520018a7fbe
R10: fffff520018a7fbe R11: 1ffff920018a7fbc R12: ffffffff8a0cded0
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000555577c2b480(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd22326ed58 CR3: 000000002b75f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1314 [inline]
__se_sys_clock_nanosleep+0x2e6/0x370 kernel/time/posix-timers.c:1291
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd223f38ef5
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007ffcfb59a4f0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007fd22402cf80 RCX: 00007fd223f38ef5
RDX: 00007ffcfb59a530 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd22402e980 R08: 0000000000000000 R09: 0017478612343624
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000003b94a
R13: ffffffffffffffff R14: 00007fd223a91000 R15: 000000000003b609