INFO: task syz.4.353:6908 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.353 state:D stack:28120 pid:6908 tgid:6907 ppid:5643 task_flags:0x400040 flags:0x08080002
Call Trace:
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]
usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411
do_dentry_open+0x785/0x14e0 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_compat_sys_openat fs/open.c:1432 [inline]
__se_compat_sys_openat fs/open.c:1430 [inline]
__ia32_compat_sys_openat+0x131/0x160 fs/open.c:1430
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
do_int80_emulation+0x181/0x530 arch/x86/entry/syscall_32.c:172
asm_int80_emulation+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0023:0xf71461ab
RSP: 002b:00000000f540603c EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 00000000f5406100
RDX: 0000000000000402 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5383:
#0: ffff888036fc90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5610:
#0: ffff8880b863aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:660
4 locks held by udevd/5642:
#0: ffff88803468d638 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183
#1: ffff8880207ca480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff888079a572d8 (kn->active#34){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888079a572d8 (kn->active#34){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff888021f161d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline]
#3: ffff888021f161d8 (&dev->mutex){....}-{4:4}, at: serial_show+0x26/0xa0 drivers/usb/core/sysfs.c:143
2 locks held by syz-executor/5647:
3 locks held by kworker/0:3/5689:
#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: ffffc9000457fc40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000457fc40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8e962e78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
3 locks held by kworker/0:5/5703:
#0: ffff88801eaa3d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801eaa3d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90004dcfc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90004dcfc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffff8880b8628fb0 (lock#6){..-.}-{3:3}, at: lock_timer_base kernel/time/timer.c:1004 [inline]
#2: ffff8880b8628fb0 (lock#6){..-.}-{3:3}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085
6 locks held by kworker/0:6/5717:
#0: ffff88801eaa3d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801eaa3d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90004eafc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90004eafc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffff88802b3ed1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#2: ffff88802b3ed1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
#3: ffff888021f161d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff888021f161d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#4: ffff88802b5cc1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff88802b5cc1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076
#5: ffffffff8e7f99e8 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214
1 lock held by syz.4.353/6908:
#0: ffff88802b3ed1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802b3ed1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054
5 locks held by syz.1.1031/9158:
#0: ffff88805684f4c8 (&runtime->oss.params_lock){+.+.}-{4:4}, at: snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1410 [inline]
#0: ffff88805684f4c8 (&runtime->oss.params_lock){+.+.}-{4:4}, at: snd_pcm_oss_write+0x207/0xbd0 sound/core/oss/pcm_oss.c:2811
#1: ffffffff8fd20de8 (snd_pcm_link_rwsem){++++}-{4:4}, at: class_rwsem_read_constructor include/linux/rwsem.h:259 [inline]
#1: ffffffff8fd20de8 (snd_pcm_link_rwsem){++++}-{4:4}, at: snd_pcm_action_nonatomic+0x33/0x2b0 sound/core/pcm_native.c:1442
#2: ffff88805684f228 (&runtime->buffer_mutex){+.+.}-{4:4}, at: snd_pcm_buffer_access_lock sound/core/pcm_native.c:740 [inline]
#2: ffff88805684f228 (&runtime->buffer_mutex){+.+.}-{4:4}, at: snd_pcm_action_nonatomic+0xe3/0x2b0 sound/core/pcm_native.c:1443
#3: ffff88802703eb78 (&chip->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#3: ffff88802703eb78 (&chip->mutex){+.+.}-{4:4}, at: snd_usb_endpoint_prepare+0x3d/0x490 sound/usb/endpoint.c:1463
#4: ffff88802b4d3960 (hcd->bandwidth_mutex){+.+.}-{4:4}, at: usb_set_interface+0x353/0x1450 drivers/usb/core/message.c:1624
=============================================
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 04/18/2026
Call Trace:
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5646 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
Code: c0 75 4c 83 3b 00 74 3a 48 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 ab 15 ba 00 48 8b 3b e8 43 dc 18 00 <85> c0 74 14 43 80 3c 37 00 74 08 48 89 df e8 90 15 ba 00 48 8b 03
RSP: 0000:ffffc900042ff288 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc900042ff2f0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8e220b28 RDI: ffffffff820796bf
RBP: ffffc900042ff330 R08: ffffc900042ff5f0 R09: 0000000000000000
R10: ffffc900042ff2f8 R11: fffff5200085fe61 R12: ffff888035723d80
R13: 1ffff11006ae486e R14: dffffc0000000000 R15: 1ffff9200085fe5e
FS: 0000000000000000(0000) GS:ffff888125287000(0063) knlGS:0000000057459480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000005746521c CR3: 000000005d878000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xcec/0x1480 mm/page_alloc.c:3004
folios_put_refs+0x9ff/0xb40 mm/swap.c:1008
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149
shmem_truncate_range mm/shmem.c:1277 [inline]
shmem_evict_inode+0x289/0xae0 mm/shmem.c:1407
evict+0x61e/0xb10 fs/inode.c:841
filename_unlinkat+0x43f/0x610 fs/namei.c:5572
__do_sys_unlink fs/namei.c:5603 [inline]
__se_sys_unlink+0x2e/0x140 fs/namei.c:5600
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x229/0x6e0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f6601c
Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8
RSP: 002b:00000000f754ecd8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00000000f754ed80 RCX: 0000000000008000
RDX: 00000000f73f4ff4 RSI: 0000000000000000 RDI: 00000000f754fe14
RBP: 00000000f754ed80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000