INFO: task kworker/u8:16:4552 blocked for more than 142 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:16 state:D stack:23608 pid:4552 tgid:4552 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common+0x2d7/0x4c0 kernel/sched/completion.c:100
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x49/0x60 kernel/sched/completion.c:153
__flush_workqueue+0x3e2/0x1230 kernel/workqueue.c:4033
rxrpc_destroy_all_connections+0xed/0x440 net/rxrpc/conn_object.c:477
rxrpc_exit_net+0x7b/0xc0 net/rxrpc/net_ns.c:113
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
cleanup_net+0x41b/0x830 net/core/net_namespace.c:696
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c9140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c9140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c9140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:16/4552:
#0: ffff88801badf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000e6a7c90 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x830 net/core/net_namespace.c:670
1 lock held by syz.3.342/7639:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
1 lock held by syz.2.376/7776:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
1 lock held by syz.0.395/7847:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
1 lock held by syz.1.411/7959:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
2 locks held by kworker/u10:22/8234:
#0: ffff888148297148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000b977c90 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
1 lock held by syz.5.469/8277:
#0: ffff888042e9f508 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888042e9f508 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:652
3 locks held by kworker/u10:24/8443:
#0: ffff88813ff69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90003d67c90 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff9012c648 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
1 lock held by syz.4.527/8610:
#0: ffff888042cb3b88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff888042cb3b88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:652
1 lock held by syz.9.593/9005:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
1 lock held by syz.2.652/9423:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
1 lock held by syz.5.682/9580:
#0: ffffffff90115ff0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x5d0 net/core/net_namespace.c:577
8 locks held by syz-executor/9662:
#0: ffff888024ade420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#1: ffff8880792be888 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x570 fs/kernfs/file.c:343
#2: ffff8880287f8698 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880287f8698 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ff/0x570 fs/kernfs/file.c:344
#3: ffffffff8f6a4c88 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x4a0 drivers/net/netdevsim/bus.c:234
#4: ffff88807b66b0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff88807b66b0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff88807b66b0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1294
#5: ffff88807b66c250 (&devlink->lock_key#5){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1777
#6: ffffffff9012c648 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x108/0x830 drivers/net/netdevsim/netdev.c:1175
#7: ffffffff8e3d48b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
9 locks held by syz.0.701/9699:
#0: ffff8880339037b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1255
#1: ffff888024ade420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#2: ffff8880a460ec88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x570 fs/kernfs/file.c:343
#3: ffff88802ad84d28 (kn->active#82){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff88802ad84d28 (kn->active#82){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ff/0x570 fs/kernfs/file.c:344
#4: ffff88802abc8710 (&atkbd->mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
#4: ffff88802abc8710 (&atkbd->mutex){+.+.}-{4:4}, at: atkbd_attr_set_helper.isra.0+0x31/0x260 drivers/input/keyboard/atkbd.c:1463
#5: ffffffff8f94ec28 (input_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
#5: ffffffff8f94ec28 (input_mutex){+.+.}-{4:4}, at: input_register_device+0x992/0x1180 drivers/input/input.c:2374
#6: ffff888084f385e0 (&led_cdev->led_access){+.+.}-{4:4}, at: led_classdev_register_ext+0x519/0xa10 drivers/leds/led-class.c:536
#7: ffffffff8ef49f90 (triggers_list_lock){++++}-{4:4}, at: led_trigger_set_default drivers/leds/led-triggers.c:297 [inline]
#7: ffffffff8ef49f90 (triggers_list_lock){++++}-{4:4}, at: led_trigger_set_default+0x89/0x2e0 drivers/leds/led-triggers.c:284
#8: ffff888084f384f8 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default drivers/leds/led-triggers.c:298 [inline]
#8: ffff888084f384f8 (&led_cdev->trigger_lock){+.+.}-{4:4}, at: led_trigger_set_default+0x92/0x2e0 drivers/leds/led-triggers.c:284
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf14/0x1140 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7248 Comm: kworker/u11:2 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci6 hci_cmd_timeout
RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:407
Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d e9 d6 64 3d 06 e8 71 52 fc fc eb a0 e8 fa 52 fc
RSP: 0018:ffffc900035a7610 EFLAGS: 00000002
RAX: 0000000000000039 RBX: 00000000000003f8 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: ffffffff85295855 RDI: ffffffff9ae6d480
RBP: ffffffff9ae6d440 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 000000006ce34620 R12: 0000000000000000
R13: 0000000000000039 R14: ffffffff9ae6d440 R15: ffffffff852957f0
FS: 0000000000000000(0000) GS:ffff888124967000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562c0537b000 CR3: 0000000031dc4000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3264 [inline]
serial8250_console_write+0xfbd/0x1890 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record+0x796/0xc60 kernel/printk/printk.c:3215
console_flush_all kernel/printk/printk.c:3289 [inline]
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xef/0x240 kernel/printk/printk.c:3359
vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
_printk+0xc7/0x100 kernel/printk/printk.c:2451
bt_err+0xe4/0x120 net/bluetooth/lib.c:296
hci_cmd_timeout+0x1ff/0x260 net/bluetooth/hci_core.c:1473
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246