INFO: task syz-executor:1384 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22128 pid:1384 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747
del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
kernfs_fop_write_iter+0x3b2/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x4b1/0xa30 fs/read_write.c:584
ksys_write+0x14c/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f03c415d04e
RSP: 002b:00007ffe8b7dddc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055557b1d3500 RCX: 00007f03c415d04e
RDX: 0000000000000001 RSI: 00007ffe8b7dde50 RDI: 0000000000000005
RBP: 00007f03c4233514 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffe8b7dde50 R14: 00007f03c4f44620 R15: 0000000000000003
INFO: task syz-executor:1391 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22640 pid:1391 ppid:1 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747
del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
kernfs_fop_write_iter+0x3b2/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x4b1/0xa30 fs/read_write.c:584
ksys_write+0x14c/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1a3135d04e
RSP: 002b:00007ffc684c3bb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000055558e680500 RCX: 00007f1a3135d04e
RDX: 0000000000000001 RSI: 00007ffc684c3c40 RDI: 0000000000000005
RBP: 00007f1a31433514 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc684c3c40 R14: 00007f1a32144620 R15: 0000000000000003
Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2df70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2e790 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by ksoftirqd/1/21:
1 lock held by khungtaskd/28:
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
5 locks held by kworker/u4:5/1176:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#1: ffffc90004c9fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd3b090 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:594
#3: ffff8880426b53e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x112/0x300 drivers/net/wireguard/device.c:249
#4: ffffffff8cb33180 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023
2 locks held by getty/4028:
#0: ffff88802ff6a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by kworker/u4:8/5064:
4 locks held by syz-executor/1384:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff8880793af888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
7 locks held by syz-executor/1388:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff888043341488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
#4: ffff88806d0fb0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#4: ffff88806d0fb0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline]
#4: ffff88806d0fb0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283
#5: ffff88806d0f82f8 (&devlink->lock_key#16){+.+.}-{3:3}, at: nsim_drv_remove+0x54/0x170 drivers/net/netdevsim/dev.c:1678
#6: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381
4 locks held by syz-executor/1391:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff88807e8fb488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1531:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff888041d64488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1644:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff88807dde1088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (
kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1649:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff88802e867488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2:
ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1655:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff888057d60c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1659:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff888053a05488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1688:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff888143bf2488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
4 locks held by syz-executor/1837:
#0: ffff88807e918460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580
#1: ffff88805aae3488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88802646eda0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
#3: ffffffff8d656e68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd4/0x360 drivers/net/netdevsim/bus.c:209
1 lock held by syz-executor/1958:
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8dd47f68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154
1 lock held by dhcpcd-run-hook/1963:
#0: ffff8880b8e3ab18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:538
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 32086 Comm: kworker/1:12 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:copy_data kernel/printk/printk_ringbuffer.c:1731 [inline]
RIP: 0010:prb_read kernel/printk/printk_ringbuffer.c:1825 [inline]
RIP: 0010:_prb_read_valid+0x7fa/0xa60 kernel/printk/printk_ringbuffer.c:1891
Code: 01 00 00 bf 01 00 00 00 4c 89 f6 e8 60 5c 1a 00 49 83 fe 01 0f 85 6a 02 00 00 e8 71 58 1a 00 41 bf fe ff ff ff e9 01 fb ff ff 61 58 1a 00 80 7c 24 0f 00 0f 85 80 00 00 00 e8 51 58 1a 00 8b
RSP: 0018:ffffc900040774a0 EFLAGS: 00000246
RAX: ffffffff81681bb0 RBX: ffffffff8ca45560 RCX: 0000000000000000
RDX: ffff88802e50bb80 RSI: 0000000000000017 RDI: 0000000000000020
RBP: ffffc90004077660 R08: ffffc900040777f7 R09: 1ffff9200080eefe
R10: dffffc0000000000 R11: fffff5200080eeff R12: ffffffff8ca45540
R13: dffffc0000000000 R14: ffffc90004077580 R15: 0000000000000017
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f874dea84e8 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
prb_read_valid+0x39/0x60 kernel/printk/printk_ringbuffer.c:1940
console_emit_next_record+0x1b3/0xba0 kernel/printk/printk.c:2735
console_flush_all kernel/printk/printk.c:-1 [inline]
console_unlock+0x223/0x630 kernel/printk/printk.c:2906
vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
_printk+0xda/0x130 kernel/printk/printk.c:2328
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query+0x351/0x460 drivers/media/usb/dvb-usb/m920x.c:-1
legacy_dvb_usb_read_remote_control+0xff/0x450 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295