INFO: task kworker/1:1:46 blocked for more than 122 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1 state:D stack:0 pid:46 tgid:46 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:6026 [inline]
__schedule+0x1399/0x1fa0 kernel/sched/core.c:7880
__schedule_loop kernel/sched/core.c:7961 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7976
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
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+0x1d4/0x380 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/1:3:357 blocked for more than 123 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3 state:D stack:0 pid:357 tgid:357 ppid:2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
context_switch kernel/sched/core.c:6026 [inline]
__schedule+0x1399/0x1fa0 kernel/sched/core.c:7880
__schedule_loop kernel/sched/core.c:7961 [inline]
schedule+0xc5/0x240 kernel/sched/core.c:7976
schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:8033
__mutex_lock_common kernel/locking/mutex.c:707 [inline]
__mutex_lock+0x960/0x1bb0 kernel/locking/mutex.c:803
__mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134
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+0x1d4/0x380 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 88ceac27f2f759e3bbd2a088bdce4bdb7d92b188
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: 1955 Comm: syz.6.536 Not tainted syzkaller #0 88ceac27f2f759e3bbd2a088bdce4bdb7d92b188
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:206 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:238 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:PageCompound include/linux/page-flags.h:296 [inline]
RIP: 0010:free_pages_prepare mm/page_alloc.c:1310 [inline]
RIP: 0010:free_unref_page+0xc4/0xf80 mm/page_alloc.c:2876
Code: 1e 14 06 0f 85 af 03 00 00 43 c6 44 3e 04 01 0f 1f 44 00 00 31 c0 88 44 24 60 48 89 df be 08 00 00 00 e8 af 2c 07 00 48 89 d8 <48> c1 e8 03 48 89 44 24 30 42 80 3c 38 00 74 08 48 89 df e8 c4 29
RSP: 0018:ffffc90003037740 EFLAGS: 00000256
RAX: ffffea0004797200 RBX: ffffea0004797200 RCX: ffffffff81d915b1
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0004797200
RBP: ffffc90003037838 R08: ffffea0004797207 R09: 1ffffd40008f2e40
R10: dffffc0000000000 R11: fffff940008f2e41 R12: 0000000000000000
R13: ffffea0004797201 R14: 1ffff92000606ef0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f410c185f40 CR3: 000000010c3fe000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000009 DR2: 0000000000000007
DR3: 8000000000000001 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__free_pages+0x6b/0x3b0 mm/page_alloc.c:5399
vfree+0x3ea/0x5b0 mm/vmalloc.c:3408
kcov_put kernel/kcov.c:439 [inline]
kcov_close+0x2c/0x70 kernel/kcov.c:535
__fput+0x1fb/0xa00 fs/file_table.c:429
____fput+0x20/0x30 fs/file_table.c:457
task_work_run+0x1e5/0x260 kernel/task_work.c:246
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x9ad/0x2720 kernel/exit.c:954
do_group_exit+0x229/0x2f0 kernel/exit.c:1096
get_signal+0x1398/0x14e0 kernel/signal.c:2933
arch_do_signal_or_restart+0xbc/0x760 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218
do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f410c19ca6b
Code: Unable to access opcode bytes at 0x7f410c19ca41.
RSP: 002b:00007f410d013f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 0000000000000005 RCX: 00007f410c19ca6b
RDX: 00007f410d014fd0 RSI: 0000000080085502 RDI: 0000000000000005
RBP: 00007f410d014fd0 R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502
R13: 0000000800000000 R14: 0000000000000005 R15: 00007f410c2511da