INFO: task kworker/1:0:31 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:0 pid:31 tgid:31 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 usb_audio_probe+0x39d/0x1d60 sound/usb/card.c:887 usb_probe_interface+0x6ac/0xc00 drivers/usb/core/driver.c:400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_set_configuration+0x1acf/0x20b0 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254 usb_probe_device+0x1d1/0x380 drivers/usb/core/driver.c:295 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_new_device+0x9f8/0x15b0 drivers/usb/core/hub.c:2703 hub_port_connect drivers/usb/core/hub.c:5574 [inline] hub_port_connect_change drivers/usb/core/hub.c:5714 [inline] port_event drivers/usb/core/hub.c:5878 [inline] hub_event+0x30c6/0x4700 drivers/usb/core/hub.c:5960 process_one_work kernel/workqueue.c:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task kworker/0:2:352 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:0 pid:352 tgid:352 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 usb_audio_probe+0x39d/0x1d60 sound/usb/card.c:887 usb_probe_interface+0x6ac/0xc00 drivers/usb/core/driver.c:400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_set_configuration+0x1acf/0x20b0 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254 usb_probe_device+0x1d1/0x380 drivers/usb/core/driver.c:295 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_new_device+0x9f8/0x15b0 drivers/usb/core/hub.c:2703 hub_port_connect drivers/usb/core/hub.c:5574 [inline] hub_port_connect_change drivers/usb/core/hub.c:5714 [inline] port_event drivers/usb/core/hub.c:5878 [inline] hub_event+0x30c6/0x4700 drivers/usb/core/hub.c:5960 process_one_work kernel/workqueue.c:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INFO: task kworker/1:5:404 blocked for more than 123 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:0 pid:404 tgid:404 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:6026 [inline] __schedule+0x14ce/0x2100 kernel/sched/core.c:7893 __schedule_loop kernel/sched/core.c:7974 [inline] schedule+0xc5/0x240 kernel/sched/core.c:7989 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8046 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x960/0x1bc0 kernel/locking/mutex.c:805 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1136 mutex_lock+0x113/0x1d0 kernel/locking/mutex.c:285 usb_audio_probe+0x39d/0x1d60 sound/usb/card.c:887 usb_probe_interface+0x6ac/0xc00 drivers/usb/core/driver.c:400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_set_configuration+0x1acf/0x20b0 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254 usb_probe_device+0x1d1/0x380 drivers/usb/core/driver.c:295 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_new_device+0x9f8/0x15b0 drivers/usb/core/hub.c:2703 hub_port_connect drivers/usb/core/hub.c:5574 [inline] hub_port_connect_change drivers/usb/core/hub.c:5714 [inline] port_event drivers/usb/core/hub.c:5878 [inline] hub_event+0x30c6/0x4700 drivers/usb/core/hub.c:5960 process_one_work kernel/workqueue.c:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 d58365df94cd5f4886b4f3ec3f08a458f2157066 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xdad/0xf00 kernel/hung_task.c:423 kthread+0x2c9/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 66 Comm: kworker/1:2 Not tainted syzkaller #0 d58365df94cd5f4886b4f3ec3f08a458f2157066 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:__sanitizer_cov_trace_cmp4+0x0/0x90 kernel/kcov.c:287 Code: 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 5d e9 d4 ae 22 04 cc 0f 1f 00 b8 69 99 69 53 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 48 8b 45 08 65 48 8b 15 8c 26 7d 7e 65 8b RSP: 0018:ffffc90000d6ec38 EFLAGS: 00000293 RAX: ffffffff846c21ff RBX: 00000000000006f5 RCX: 0000000000000000 RDX: ffff888106372600 RSI: 0000000000000006 RDI: 0000000000000001 RBP: ffffc90000d6ee00 R08: ffff888106372600 R09: 0000000000000020 R10: 00000000000000bc R11: 0000000000000000 R12: 0000000000000006 R13: ffff888118af810d R14: 00000000000006f5 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f914d785fc0 CR3: 0000000128844000 CR4: 00000000003526b0 Call Trace: snd_usb_parse_audio_interface+0x3e/0xd0 sound/usb/stream.c:1280 snd_usb_create_stream+0x3df/0x540 sound/usb/card.c:279 snd_usb_create_streams sound/usb/card.c:400 [inline] usb_audio_probe+0x1319/0x1d60 sound/usb/card.c:967 usb_probe_interface+0x6ac/0xc00 drivers/usb/core/driver.c:400 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_set_configuration+0x1acf/0x20b0 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0x95/0x160 drivers/usb/core/generic.c:254 usb_probe_device+0x1d1/0x380 drivers/usb/core/driver.c:295 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d8/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x264/0x300 drivers/base/bus.c:459 __device_attach+0x2c9/0x3c0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xbf0 drivers/base/core.c:3692 usb_new_device+0x9f8/0x15b0 drivers/usb/core/hub.c:2703 hub_port_connect drivers/usb/core/hub.c:5574 [inline] hub_port_connect_change drivers/usb/core/hub.c:5714 [inline] port_event drivers/usb/core/hub.c:5878 [inline] hub_event+0x30c6/0x4700 drivers/usb/core/hub.c:5960 process_one_work kernel/workqueue.c:3261 [inline] process_scheduled_works+0x7d4/0x1020 kernel/workqueue.c:3342 worker_thread+0xc51/0x1370 kernel/workqueue.c:3423 kthread+0x2c9/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244