INFO: task kworker/u8:8:6296 blocked for more than 244 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8 state:D stack:23464 pid:6296 tgid:6296 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4194
process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3421
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
INFO: task syz.4.5676:27281 blocked for more than 244 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.5676 state:D stack:26584 pid:27281 tgid:27281 ppid:17754 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
exp_funnel_lock+0x344/0x3c0 kernel/rcu/tree_exp.h:334
synchronize_rcu_expedited+0x298/0x450 kernel/rcu/tree_exp.h:956
namespace_unlock+0x63b/0xa40 fs/namespace.c:1715
class_namespace_excl_destructor fs/namespace.c:96 [inline]
dissolve_on_fput+0x308/0x4e0 fs/namespace.c:2307
__fput+0x990/0xb40 fs/file_table.c:478
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffb1499af79
RSP: 002b:00007ffd757efab8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffb14c17da0 RCX: 00007ffb1499af79
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007ffb14c17da0 R08: 0000000000000006 R09: 0000000000000000
R10: 00007ffb14c17cb0 R11: 0000000000000246 R12: 0000000000192c1c
R13: 00007ffb14c1609c R14: 0000000000192045 R15: 00007ffd757efbc0
INFO: task syz.0.5680:27295 blocked for more than 245 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.5680 state:D stack:28392 pid:27295 tgid:27295 ppid:17020 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0xfe6/0x5fa0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:6964
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
tun_detach drivers/net/tun.c:634 [inline]
tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
__fput+0x3ff/0xb40 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x100/0x4b0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4843f9af79
RSP: 002b:00007ffdd01b9f88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffdd01ba070 RCX: 00007f4843f9af79
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000019224a R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b33320000 R11: 0000000000000246 R12: 00007ffdd01ba0b0
R13: 00007f4844215fac R14: 000000000019229c R15: 00007f4844215fa0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
6 locks held by kworker/1:2/793:
#0: ffff888020eb4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc90003547c98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888029a7c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888029a7c198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888037f78198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888037f78198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336
#4: ffff888037f7b160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff888037f7b160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline]
#4: ffff888037f7b160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xaa/0x600 drivers/base/dd.c:1304
#5: ffffffff8fbfeda8 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#5: ffffffff8fbfeda8 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x184/0x4d0 drivers/input/input.c:2187
2 locks held by getty/5570:
#0: ffff88814e2870a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:7/5820:
#0: ffff88807b0e9148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9000426fc98 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888059fc8ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open+0x22/0xb0 net/bluetooth/hci_core.c:428
5 locks held by kworker/1:4/5882:
#0: ffff888020eb4d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9000445fc98 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffff888029a54198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888029a54198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899
#3: ffff888029a57518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
#3: ffff888029a57518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
#3: ffff888029a57518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#3: ffff888029a57518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#3: ffff888029a57518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2bd2/0x4af0 drivers/usb/core/hub.c:5953
#4: ffff8880299cfa68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
#4: ffff8880299cfa68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
#4: ffff8880299cfa68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
#4: ffff8880299cfa68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2bfb/0x4af0 drivers/usb/core/hub.c:5953
3 locks held by kworker/u8:8/6296:
#0: ffff8880315c3948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9000c07fc98 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4194
3 locks held by kworker/1:0/16103:
#0: ffff88813fe51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x11ae/0x1840 kernel/workqueue.c:3232
#1: ffffc9001047fc98 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x927/0x1840 kernel/workqueue.c:3233
#2: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by syz.0.4375/22675:
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
1 lock held by syz.4.4392/22735:
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
1 lock held by syz.5.4919/24610:
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
1 lock held by udevd/26227:
#0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
#0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
1 lock held by syz.1.5671/27269:
1 lock held by syz.4.5676/27285:
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x307/0xb40 net/core/rtnetlink.c:3562
2 locks held by syz.4.5676/27288:
#0: ffff88807ea7e3c8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff88807ea7e3c8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661
#1: ffffffff8e5efab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.0.5680/27295:
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff903f36a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
2 locks held by dhcpcd/27303:
#0: ffff8880390d4148 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#0: ffff8880390d4148 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661
#1: ffffffff8e5efab8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 0
CPU: 0 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 01/24/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xcc3/0xfe0 kernel/hung_task.c:515
kthread+0x3b3/0x730 kernel/kthread.c:463
ret_from_fork+0x754/0xaf0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 1 Comm: init Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:kasan_byte_accessible+0x0/0x30 mm/kasan/generic.c:204
Code: 0c 24 ba 01 00 00 00 e9 de fd ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 48 b8 00 00 00 00 00 fc ff df 48 c1 ef 03 48 01 c7 0f
RSP: 0018:ffffc90000067628 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff81b6a0a1 RDI: ffffffff8e5e32e0
RBP: ffffffff8e5e32e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 000000000001a5b8 R12: ffffffff81b6a0a1
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fb7535a0c80(0000) GS:ffff8881246d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000016000 CR3: 0000000036bf7000 CR4: 00000000003526f0
Call Trace:
__kasan_check_byte+0x13/0x50 mm/kasan/common.c:573
kasan_check_byte include/linux/kasan.h:402 [inline]
lock_acquire kernel/locking/lockdep.c:5842 [inline]
lock_acquire+0xf5/0x330 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x2ad/0x780 mm/slub.c:5270
locks_alloc_lock fs/locks.c:275 [inline]
posix_lock_inode+0x5b2/0x23e0 fs/locks.c:1224
posix_lock_file fs/locks.c:1451 [inline]
vfs_lock_file+0xfb/0x150 fs/locks.c:2417
do_lock_file_wait fs/locks.c:2431 [inline]
fcntl_setlk+0x469/0xde0 fs/locks.c:2509
do_fcntl+0xf39/0x1670 fs/fcntl.c:500
__do_sys_fcntl fs/fcntl.c:602 [inline]
__se_sys_fcntl fs/fcntl.c:587 [inline]
__x64_sys_fcntl+0x163/0x200 fs/fcntl.c:587
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb75375eadd
Code: 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 c7 44 24 b8 10 00 00 00 48 89 44 24 c8 83 fe 09 74 1a b8 48 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 23 c3 66 2e 0f 1f 84 00 00 00 00 00 48 8d 54
RSP: 002b:00007fffe66a99a8 EFLAGS: 00000293 ORIG_RAX: 0000000000000048
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb75375eadd
RDX: 00007fffe66a99b0 RSI: 0000000000000007 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fffe66a99d0 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000293 R12: 0000000000000000
R13: 00007fffe66a99d0 R14: 0000000000000002 R15: 00005631be7b0d98