INFO: task kworker/0:2:2224 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:21264 pid:2224 tgid:2224 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events request_firmware_work_func Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1138/0x47e0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 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+0xced/0x1b10 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+0x3b5/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 request_firmware_work_func+0x13c/0x250 drivers/base/firmware_loader/main.c:1152 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314 process_scheduled_works kernel/workqueue.c:3397 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.4.720:8078 blocked for more than 171 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.720 state:D stack:26984 pid:8078 tgid:8077 ppid:2974 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1138/0x47e0 kernel/sched/core.c:7189 do_task_dead+0xca/0x100 kernel/sched/core.c:7207 do_exit+0x17bd/0x2af0 kernel/exit.c:1019 do_group_exit+0xd5/0x2a0 kernel/exit.c:1119 get_signal+0x20ff/0x2210 kernel/signal.c:3037 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x83/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x682/0x7f0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0a9c92caeb RSP: 002b:00007f0a9b37cf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffffc RBX: 0000000000000003 RCX: 00007f0a9c92caeb RDX: 00007f0a9b37dfd0 RSI: 0000000080085502 RDI: 0000000000000003 RBP: 00007f0a9b37dfd0 R08: 0000000000000008 R09: 00007f0a9b37cfc8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000008 R15: 00007f0a9c9e125f Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff896de960 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/35: #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90000257d18 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 6 locks held by kworker/1:1/37: 3 locks held by kworker/1:2/1076: #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc900035afd18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88810b3521d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810b3521d8 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] #2: ffff88810b3521d8 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x3b5/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 3 locks held by kworker/0:2/2224: #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90005e0fd18 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88810b3921d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810b3921d8 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_fail drivers/net/wireless/ath/ath9k/hif_usb.c:1161 [inline] #2: ffff88810b3921d8 (&dev->mutex){....}-{4:4}, at: ath9k_hif_usb_firmware_cb+0x3b5/0x530 drivers/net/wireless/ath/ath9k/hif_usb.c:1294 1 lock held by acpid/2844: #0: ffffffff896ea4a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by udevd/2859: #0: ffff888100e87980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x7e0 fs/kernfs/dir.c:1218 2 locks held by getty/2921: #0: ffff8881132050a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/2972: 2 locks held by syz-executor/2974: 1 lock held by syz-executor/2975: 2 locks held by syz-executor/2976: 2 locks held by syz-executor/2980: 7 locks held by kworker/1:3/5231: #0: ffff888105a82940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3289 #1: ffffc90001fefd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3290 #2: ffff88810af921d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88810af921d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff888117a5f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff888117a5f1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff88810a3251a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff88810a3251a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff88810a3251a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1372 #5: ffffffff8a515a20 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffffffff8a515a20 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x156/0x470 drivers/input/input.c:2204 #6: ffffffff896ea4a8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 2 locks held by udevd/5236: 6 locks held by kworker/1:5/5241: 4 locks held by udevd/5248: #0: ffff888107f6bf38 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88811e95a080 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888124a4a968 (kn->active#12){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888124a4a968 (kn->active#12){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888117a5f1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff888117a5f1d8 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143 3 locks held by kworker/0:6/5380: 2 locks held by syz.3.722/8083: 2 locks held by syz.1.725/8096: 2 locks held by syz.0.726/8098: 2 locks held by syz-executor/8102: 1 lock held by syz-executor/8103: 2 locks held by syz-executor/8104: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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:162 [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:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2848 Comm: klogd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline] RIP: 0010:stack_access_ok+0x9b/0x1d0 arch/x86/kernel/unwind_orc.c:409 Code: 03 80 3c 02 00 0f 85 0b 01 00 00 48 8b 43 10 49 39 ed 77 1a 48 39 e8 76 15 4a 8d 54 25 00 48 39 d0 0f 93 c0 49 39 d5 0f 92 c2 <20> d0 75 38 48 8d 7b 28 48 8d 4b 20 48 b8 00 00 00 00 00 fc ff df RSP: 0018:ffffc9000149f4d0 EFLAGS: 00000283 RAX: ffffc900014a0001 RBX: ffffc9000149f570 RCX: ffffffff8bc7d0b4 RDX: ffffc9000149ff01 RSI: ffffc9000149ff48 RDI: ffffc9000149f580 RBP: ffffc9000149ff48 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000066d9d R12: 0000000000000008 R13: ffffc90001498000 R14: ffffc9000149ff58 R15: ffffc9000149f5a4 FS: 00007f4bbf700c80(0000) GS:ffff8882687a5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4f06d12050 CR3: 00000001175c2000 CR4: 00000000003506f0 Call Trace: deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline] unwind_next_frame+0x1551/0x2090 arch/x86/kernel/unwind_orc.c:677 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+0x6e/0x70 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_node_noprof+0x26b/0x6b0 mm/slub.c:4951 __alloc_skb+0x140/0x710 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1385 [inline] alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6766 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:2998 unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2141 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x468/0x4b0 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4bbf850407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffe62bd77b0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f4bbf700c80 RCX: 00007f4bbf850407 RDX: 000000000000004a RSI: 00007ffe62bd78f0 RDI: 0000000000000003 RBP: 00007ffe62bd7d20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffe62bd7d38 R13: 00007ffe62bd78f0 R14: 000000000000002f R15: 00007ffe62bd78f0