INFO: task syz-executor.4:15847 blocked for more than 143 seconds.
Not tainted 6.1.35-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:27368 pid:15847 ppid:3606 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0x132c/0x4330 kernel/sched/core.c:6554
schedule+0xbf/0x180 kernel/sched/core.c:6630
schedule_timeout+0xac/0x300 kernel/time/timer.c:1911
do_wait_for_common+0x441/0x5e0 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+0x46/0x60 kernel/sched/completion.c:138
__flush_workqueue+0x737/0x1610 kernel/workqueue.c:2861
nbd_start_device_ioctl drivers/block/nbd.c:1425 [inline]
__nbd_ioctl drivers/block/nbd.c:1487 [inline]
nbd_ioctl+0xaf6/0xe70 drivers/block/nbd.c:1527
blkdev_ioctl+0x3a9/0x760 block/ioctl.c:615
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f8e2188c389
RSP: 002b:00007f8e225b9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8e219abf80 RCX: 00007f8e2188c389
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000007
RBP: 00007f8e218d7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc284060af R14: 00007f8e225b9300 R15: 0000000000022000
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cf27470 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cf27c70 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510
1 lock held by khungtaskd/28:
#0: ffffffff8cf272a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3299:
#0: ffff888028bf1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2177
1 lock held by syz-fuzzer/3703:
#0: ffff8880b9839dd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
2 locks held by kworker/u5:2/3603:
#0: ffff88801f513138 ((wq_completion)nbd4-recv){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0
#1: ffffc9000410fd20 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264
3 locks held by kworker/u4:12/6883:
#0: ffff8880b9839dd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537
#1: ffff8880b9827788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a3/0x770 kernel/sched/psi.c:940
#2: ffff8880b9828358 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x62d/0xee0 kernel/time/timer.c:1096
1 lock held by syz-executor.4/19474:
#0: ffff88801f507198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x149/0xe70 drivers/block/nbd.c:1520
1 lock held by syz-executor.4/19483:
#0: ffff88801f50b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x148/0xa10 block/bdev.c:813
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.35-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf18/0xf60 kernel/hung_task.c:377
kthread+0x26e/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3708 Comm: kworker/0:8 Not tainted 6.1.35-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Workqueue: rcu_gp wait_rcu_exp_gp
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0xcf/0xa20 kernel/locking/lockdep.c:5680
Code: 0c 0f 86 c2 05 00 00 89 db 48 89 d8 48 c1 e8 06 48 8d 3c c5 68 2a 53 8e be 08 00 00 00 e8 f9 27 76 00 48 0f a3 1d 39 31 e9 0c <73> 0d e8 4a d8 08 00 84 c0 0f 84 c5 05 00 00 48 c7 c0 24 5f 53 8e
RSP: 0018:ffffc900047bf580 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8169f927
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e532a68
RBP: ffffc900047bf6b8 R08: dffffc0000000000 R09: fffffbfff1ca654e
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920008f7ebc
R13: ffffffff81680f8d R14: ffff8880b9827780 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e124000 CR3: 0000000028464000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
do_write_seqcount_end include/linux/seqlock.h:561 [inline]
psi_group_change+0xadd/0x1310 kernel/sched/psi.c:828
psi_task_switch+0x43d/0x770 kernel/sched/psi.c:952
psi_sched_switch kernel/sched/stats.h:199 [inline]
__schedule+0x1ec8/0x4330 kernel/sched/core.c:6549
schedule+0xbf/0x180 kernel/sched/core.c:6630
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935
synchronize_rcu_expedited_wait_once kernel/rcu/tree_exp.h:571 [inline]
synchronize_rcu_expedited_wait kernel/rcu/tree_exp.h:622 [inline]
rcu_exp_wait_wake kernel/rcu/tree_exp.h:690 [inline]
rcu_exp_sel_wait_wake+0x76c/0x1db0 kernel/rcu/tree_exp.h:724
process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289
worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436
kthread+0x26e/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306