INFO: task syz.2.5405:24178 blocked for more than 143 seconds.
Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.5405 state:D stack:27936 pid:24178 tgid:24167 ppid:16609 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0xf43/0x5890 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6857
schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:95 [inline]
__wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116
__flush_workqueue+0x3dc/0x1260 kernel/workqueue.c:4000
nbd_start_device_ioctl drivers/block/nbd.c:1541 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0x308/0xd60 drivers/block/nbd.c:1642
blkdev_ioctl+0x276/0x6d0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3dfd18d169
RSP: 002b:00007f3dfdf0e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3dfd3a6160 RCX: 00007f3dfd18d169
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006
RBP: 00007f3dfd20e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3dfd3a6160 R15: 00007ffd422cf398
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
1 lock held by khungtaskd/31:
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1bd140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
2 locks held by getty/5575:
#0: ffff88814d70b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
4 locks held by kworker/1:6/21568:
#0: ffff88801e2b8148 ((wq_completion)pm){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc9000411fd18 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
#2: ffff8880295ab190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#2: ffff8880295ab190 (&dev->mutex){....}-{4:4}, at: usb_remote_wakeup+0x21/0xe0 drivers/usb/core/hub.c:3854
#3: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline]
#3: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591
2 locks held by kworker/u9:0/22625:
#0: ffff88802617a948 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc9000504fd18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
3 locks held by kworker/u8:9/25329:
#0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc90005b47d18 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
#2: ffffffff8e1c8480 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x700 kernel/rcu/tree.c:3741
2 locks held by kworker/u8:39/25352:
#0: ffff88801cfb5948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213
#1: ffffc90004befd18 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214
5 locks held by syz.5.5903/26136:
#0: ffffffff8ff98cf0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffff8881446b90e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
#1: ffff8881446b90e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#1: ffff8881446b90e8 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x2fe/0x420 net/devlink/netlink.c:198
#2: ffff88814d61d250 (&devlink->lock_key#11){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#2: ffff88814d61d250 (&devlink->lock_key#11){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x306/0x420 net/devlink/netlink.c:198
#3: ffffffff8fef7f68 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x9d/0x710 drivers/net/netdevsim/netdev.c:1016
#4: ffffffff8e1c85b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:302
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0xf62/0x12b0 kernel/hung_task.c:399
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111