INFO: task syz.5.680:8759 blocked for more than 144 seconds.
Not tainted 6.15.0-rc3-syzkaller-00008-ga33b5a08cbbd #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.680 state:D stack:26360 pid:8759 tgid:8758 ppid:7232 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
__mutex_lock_common kernel/locking/mutex.c:678 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
snd_seq_info_clients_read+0x191/0x920 sound/core/seq/seq_clientmgr.c:2729
snd_info_seq_show+0xcd/0x120 sound/core/info.c:342
seq_read_iter+0x506/0x12c0 fs/seq_file.c:230
seq_read+0x39e/0x4e0 fs/seq_file.c:162
pde_read fs/proc/inode.c:308 [inline]
proc_reg_read+0x23d/0x330 fs/proc/inode.c:320
do_loop_readv_writev fs/read_write.c:845 [inline]
do_loop_readv_writev fs/read_write.c:833 [inline]
vfs_readv+0x6bc/0x8a0 fs/read_write.c:1018
do_readv+0x132/0x330 fs/read_write.c:1078
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdfe498e169
RSP: 002b:00007fdfe5788038 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 00007fdfe4bb5fa0 RCX: 00007fdfe498e169
RDX: 0000000000000001 RSI: 00002000000038c0 RDI: 0000000000000007
RBP: 00007fdfe4a10a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdfe4bb5fa0 R15: 00007fffb2a79e08
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
5 locks held by kworker/1:2/951:
#0: ffff8880222d8548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000396fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff8881453ea198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#2: ffff8881453ea198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859
#3: ffff88805b94c198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#3: ffff88805b94c198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1005
#4: ffff8880794ae160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff8880794ae160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1005
2 locks held by pvrusb2-context/2327:
#0: ffff88807188c188 (&hdw->big_lock_mutex){+.+.}-{4:4}, at: pvr2_hdw_initialize+0xb6/0x4510 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326
#1: ffffffff8e273f90 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xa9/0x250 kernel/umh.c:214
2 locks held by getty/5592:
#0: ffff888032aea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000334b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
6 locks held by kworker/0:3/5869:
#0: ffff8880222d8548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc90003a07d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff8880299e3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#2: ffff8880299e3198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859
#3: ffff888055810198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#3: ffff888055810198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x920 drivers/usb/core/hub.c:2307
#4: ffff888055817160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
#4: ffff888055817160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
#4: ffff888055817160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xa4/0x620 drivers/base/dd.c:1293
#5: ffff88807188c188 (&hdw->big_lock_mutex){+.+.}-{4:4}, at: pvr2_hdw_disconnect+0x8a/0x630 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2710
4 locks held by udevd/5975:
#0: ffff88802537d418 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#1: ffff88805b6c1888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154
#2: ffff88803369f2d8 (kn->active#27){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155
#3: ffff888055810198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:927 [inline]
#3: ffff888055810198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by kworker/u8:9/6039:
#0: ffff8880b8439dd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:613 [inline]
#0: ffff8880b8439dd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:598
#1: ffff8880b8423c48 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987
1 lock held by syz.2.279/7032:
#0: ffff88805dc089d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_ioctl+0x1eb/0x410 sound/core/seq/seq_clientmgr.c:2370
3 locks held by syz.5.680/8759:
#0: ffff888035421438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213
#1: ffff8880352e59e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12c0 fs/seq_file.c:182
#2: ffff88805dc089d0 (&client->ioctl_mutex){+.+.}-{4:4}, at: snd_seq_info_clients_read+0x191/0x920 sound/core/seq/seq_clientmgr.c:2729
1 lock held by syz.4.1042/10551:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00008-ga33b5a08cbbd #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:437
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
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: 7812 Comm: kworker/u8:12 Not tainted 6.15.0-rc3-syzkaller-00008-ga33b5a08cbbd #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound flush_to_ldisc
RIP: 0010:write_comp_data+0x0/0x90 kernel/kcov.c:240
Code: 48 8b 05 cb 96 eb 11 48 8b 80 30 16 00 00 c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <49> 89 d2 49 89 f8 49 89 f1 65 48 8b 15 97 96 eb 11 65 8b 05 a8 96
RSP: 0018:ffffc9000c206f10 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 0000000000003433 RCX: ffffffff8b6ed3d2
RDX: 0000000000000044 RSI: 0000000000000063 RDI: 0000000000000007
RBP: ffffc9000c206fd8 R08: 0000000000000007 R09: 0000000000000063
R10: 0000000000001abb R11: 000000000004afc0 R12: 000000000000002b
R13: 0000000000000044 R14: ffffc9008c20733f R15: ffffc9000c206fd8
FS: 0000000000000000(0000) GS:ffff8881249b2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe01657fab8 CR3: 0000000055b4a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
put_dec_trunc8+0x162/0x370 lib/vsprintf.c:251
number+0xa7d/0xc70 lib/vsprintf.c:505
vsnprintf+0x5e6/0x1160 lib/vsprintf.c:2816
sprintf+0xcc/0x100 lib/vsprintf.c:3015
print_time kernel/printk/printk.c:1381 [inline]
info_print_prefix+0x25a/0x350 kernel/printk/printk.c:1407
record_print_text+0x140/0x400 kernel/printk/printk.c:1456
printk_get_next_message+0x2d1/0x6d0 kernel/printk/printk.c:3024
console_emit_next_record kernel/printk/printk.c:3092 [inline]
console_flush_all+0x6ea/0xc60 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
_printk+0xc7/0x100 kernel/printk/printk.c:2475
bt_err+0xe4/0x120 net/bluetooth/lib.c:296
h5_rx_3wire_hdr+0x201/0xa50 drivers/bluetooth/hci_h5.c:459
h5_recv+0x2f0/0x910 drivers/bluetooth/hci_h5.c:585
hci_uart_tty_receive+0x251/0x7e0 drivers/bluetooth/hci_ldisc.c:627
tty_ldisc_receive_buf+0x157/0x1a0 drivers/tty/tty_buffer.c:391
tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37
receive_buf drivers/tty/tty_buffer.c:445 [inline]
flush_to_ldisc+0x268/0x780 drivers/tty/tty_buffer.c:495
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245