syzbot

INFO: task kworker/1:5:17702 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:5     state:D stack:22216 pid:17702 tgid:17702 ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0x14ef/0x4fb0 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0x164/0x360 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+0x7fe/0x1300 kernel/locking/mutex.c:776
 usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 hub_event+0x631/0x4f30 drivers/usb/core/hub.c:5952
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Showing all locks held in the system:
2 locks held by kthreadd/2:
1 lock held by khungtaskd/31:
 #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/0:2/797:
3 locks held by kworker/u8:8/1341:
3 locks held by kworker/R-ipv6_/3185:
 #0: ffff88814d0d6948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88814d0d6948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
 #1: ffffc9000b497bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000b497bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
 #2: ffffffff8f7a9d88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8f7a9d88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734
2 locks held by kworker/R-bat_e/3410:
2 locks held by udevd/5195:
3 locks held by dhcpcd/5489:
1 lock held by crond/5566:
2 locks held by getty/5584:
 #0: ffff88814d67d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000362b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5812:
4 locks held by kworker/0:3/5896:
2 locks held by kworker/0:8/5961:
3 locks held by kworker/u8:10/10045:
3 locks held by kworker/u8:19/10062:
2 locks held by kworker/0:0/11255:
8 locks held by kworker/1:2/13357:
2 locks held by kworker/0:1/14839:
3 locks held by kworker/u8:1/15645:
3 locks held by kworker/u8:4/16701:
3 locks held by kworker/u8:6/16703:
3 locks held by kworker/u8:12/16709:
5 locks held by kworker/u8:15/16716:
3 locks held by kworker/u8:16/16720:
4 locks held by kworker/1:5/17702:
 #0: ffff888142ef7148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff888142ef7148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
 #1: ffffc90004997bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc90004997bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
 #2: ffff888028a9f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff888028a9f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
 #3: ffff888032ab0518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 #3: ffff888032ab0518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x631/0x4f30 drivers/usb/core/hub.c:5952
2 locks held by kworker/0:4/18351:
4 locks held by kworker/0:5/18394:
2 locks held by syz-executor/18754:
1 lock held by dhcpcd/19559:
3 locks held by udevd/19945:
3 locks held by kworker/1:7/20001:
 #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
 #1: ffffc9000387fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000387fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
 #2: ffffffff8f7a9d88 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
4 locks held by kworker/1:8/20002:
1 lock held by syz.7.3429/20781:
1 lock held by syz.8.3435/20816:
6 locks held by syz.9.3436/20807:
3 locks held by kworker/u8:0/20817:
3 locks held by kworker/u8:2/20818:
3 locks held by kworker/u8:3/20819:
 #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
 #1: ffffc9000b5c7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000b5c7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
 #2: ffffffff8f7a9d88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by syz-executor/20821:

=============================================

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 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xf90/0xfe0 kernel/hung_task.c:515
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16716 Comm: kworker/u8:15 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: events_unbound cfg80211_wiphy_work
RIP: 0010:__dev_queue_xmit+0x6a2/0x32b0 net/core/dev.c:4797
Code: 84 c0 4c 8b 74 24 08 0f 84 25 15 00 00 e8 86 a6 72 f8 eb 0a e8 7f a6 72 f8 4c 8b 74 24 08 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 e7 e8 a4 ac d9 f8 49 83 3c 24 00 74 78 4c 89 e0 4c 8b
RSP: 0018:ffffc90000a07800 EFLAGS: 00000246
RAX: 1ffff110043fb400 RBX: 0000000000000001 RCX: ffff88806ce39e80
RDX: 0000000000000100 RSI: ffffffff8be73860 RDI: ffffffff8be73820
RBP: ffffc90000a07ab0 R08: ffffffff8fceef77 R09: 1ffffffff1f9ddee
R10: dffffc0000000000 R11: fffffbfff1f9ddef R12: ffff888021fda000
R13: dffffc0000000000 R14: ffff888038ffd280 R15: ffff88803004c000
FS:  0000000000000000(0000) GS:ffff888125a26000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000003af030 CR3: 0000000031332000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 br_dev_queue_push_xmit+0x6d2/0x8b0 net/bridge/br_forward.c:53
 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318
 br_nf_post_routing+0xb66/0xfe0 net/bridge/br_netfilter_hooks.c:966
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66
 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1167 [inline]
 br_nf_forward_finish+0xa5e/0xe90 net/bridge/br_netfilter_hooks.c:662
 NF_HOOK+0x64e/0x6e0 include/linux/netfilter.h:318
 br_nf_forward_ip+0x647/0x7e0 net/bridge/br_netfilter_hooks.c:716
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK+0x23e/0x3f0 include/linux/netfilter.h:316
 __br_forward+0x397/0x540 net/bridge/br_forward.c:115
 br_handle_frame_finish+0x1492/0x1b40 net/bridge/br_input.c:229
 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
 br_nf_pre_routing_finish_ipv6+0xa3a/0xd70 net/bridge/br_netfilter_ipv6.c:-1
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x374/0x6f0 net/bridge/br_netfilter_ipv6.c:184
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0x989/0x1520 net/bridge/br_input.c:442
 __netif_receive_skb_core+0x98f/0x30a0 net/core/dev.c:6039
 __netif_receive_skb_one_core net/core/dev.c:6150 [inline]
 __netif_receive_skb+0x72/0x370 net/core/dev.c:6265
 process_backlog+0x54e/0x1340 net/core/dev.c:6617
 __napi_poll+0xae/0x320 net/core/dev.c:7681
 napi_poll net/core/dev.c:7744 [inline]
 net_rx_action+0x696/0xe30 net/core/dev.c:7896
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 cfg80211_inform_single_bss_data+0x13b9/0x1ab0 net/wireless/scan.c:2389
 cfg80211_inform_bss_data+0x233/0x3bb0 net/wireless/scan.c:3228
 cfg80211_inform_bss_frame_data+0x3c7/0x710 net/wireless/scan.c:3319
 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230
 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1575 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1901/0x2c80 net/mac80211/ibss.c:1602
 ieee80211_iface_process_skb net/mac80211/iface.c:1740 [inline]
 ieee80211_iface_work+0x85e/0x12b0 net/mac80211/iface.c:1794
 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0x89f/0xd90 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>