syzbot

INFO: task kworker/1:4:12137 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/1:4     state:D stack:15512 pid:12137 tgid:12137 ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: events request_firmware_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
 device_lock include/linux/device.h:1040 [inline]
 ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline]
 ath9k_hif_usb_firmware_cb+0x335/0x4c0 drivers/net/wireless/ath/ath9k/hif_usb.c:1294
 request_firmware_work_func+0x105/0x1c0 drivers/base/firmware_loader/main.c:1152
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5387:
 #0: ffff888032a040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:4/12137:
 #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc9000d7efc40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc9000d7efc40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff88802b8f51d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802b8f51d8 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline]
 #2: ffff88802b8f51d8 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x335/0x4c0 drivers/net/wireless/ath/ath9k/hif_usb.c:1294
3 locks held by kworker/u8:24/18948:
 #0: ffff8880327d7940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff8880327d7940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc900046cfc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc900046cfc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4746
6 locks held by kworker/0:4/11183:
 #0: ffff88801ee91140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801ee91140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90015e27c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90015e27c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff88802b7831d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802b7831d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
 #3: ffff888036c5c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #3: ffff888036c5c1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
 #4: ffff88807d3831a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #4: ffff88807d3831a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
 #5: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
 #5: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11536
4 locks held by udevd/15480:
 #0: ffff88803443f518 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
 #1: ffff88803587b880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
 #2: ffff888054ea11e8 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888054ea11e8 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
 #3: ffff888033d061d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline]
 #3: ffff888033d061d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
4 locks held by udevd/15483:
 #0: ffff88803443fbd8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
 #1: ffff88802a432880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
 #2: ffff88802f5d9c38 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802f5d9c38 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
 #3: ffff888036c5c1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline]
 #3: ffff888036c5c1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
6 locks held by kworker/1:3/18998:
 #0: ffff88801ee91140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801ee91140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90004f27c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90004f27c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff88802b8f51d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802b8f51d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
 #3: ffff888033d061d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #3: ffff888033d061d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
 #4: ffff88806b26e1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #4: ffff88806b26e1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
 #5: ffffffff8e7f9a28 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214
3 locks held by kworker/u8:9/19307:
 #0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90003237c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90003237c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by syz.0.12544/21679:
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
1 lock held by syz.1.12558/21694:
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
1 lock held by syz.5.12573/21755:
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3083
1 lock held by syz.5.12573/21756:
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7003
2 locks held by syz.6.12574/21757:
 #0: ffff8880586dbbc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff8880586dbbc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline]
 #0: ffff8880586dbbc0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514
 #1: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #1: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.3.12579/21770:
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3083
1 lock held by syz.3.12579/21771:
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdc7f00 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7003

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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:162 [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:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:tick_program_event+0x0/0x120 kernel/time/tick-oneshot.c:28
Code: 1d 0f 00 48 c7 c7 c0 e9 47 9a e8 cb b5 fb ff 31 c0 e9 14 b0 f3 09 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 55 41 57 41 56 41 55 41 54 53 89 f5 48 89 fb 49 bd 00
RSP: 0018:ffffc90000007ed8 EFLAGS: 00000046
RAX: ffffffff81b2af04 RBX: ffff8880b8628280 RCX: ffffffff8e692ec0
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 00000353475358d1
RBP: ffff8880b8628628 R08: ffffffff903021f7 R09: 1ffffffff206043e
R10: dffffc0000000000 R11: fffffbfff206043f R12: 7fffffffffffffff
R13: 0000000000000246 R14: dffffc0000000000 R15: ffff8880b86282f8
FS:  0000000000000000(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555575a0d4e8 CR3: 00000000797ce000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 hrtimer_update_softirq_timer kernel/time/hrtimer.c:1309 [inline]
 hrtimer_run_softirq+0x1ee/0x240 kernel/time/hrtimer.c:2014
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: cb 7e 02 e9 d3 f8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 11 22 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e607dc0 EFLAGS: 00000246
RAX: 0000000004392b0f RBX: ffffffff819a858a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dfa30aa RDI: ffffffff8c28b760
RBP: ffffffff8e607eb0 R08: ffff8880b86339db R09: 1ffff110170c673b
R10: dffffc0000000000 R11: ffffed10170c673c R12: 0000000000000000
R13: 1ffffffff1cd25d8 R14: 0000000000000000 R15: 1ffffffff1cd25d8
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
 rest_init+0x2de/0x300 init/main.c:762
 start_kernel+0x38a/0x3e0 init/main.c:1220
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>