INFO: task syz.2.859:8939 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.859 state:D stack:27112 pid:8939 tgid:8938 ppid:5867 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
bdev_open+0xe0/0xd30 block/bdev.c:945
blkdev_open+0x457/0x600 block/fops.c:694
do_dentry_open+0x953/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3895 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4054
do_filp_open+0x1fa/0x410 fs/namei.c:4081
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f85af98d510
RSP: 002b:00007f85b08f1b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000080 RCX: 00007f85af98d510
RDX: 0000000000000080 RSI: 00007f85b08f1c10 RDI: 00000000ffffff9c
RBP: 00007f85b08f1c10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f85afbd6038 R14: 00007f85afbd5fa0 R15: 00007ffc48b395e8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:3/37:
2 locks held by getty/5621:
#0: ffff88814d9120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5874:
#0: ffff888143793358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by udevd/6007:
#0: ffff888025873358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.2.859/8939:
#0: ffff888025873358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
1 lock held by syz.5.1998/12422:
#0: ffff888027e129f0 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x22e/0xe90 virt/kvm/kvm_main.c:4435
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 5949 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events dvb_usb_read_remote_control
RIP: 0010:select_task_rq_fair+0x0/0x3570 kernel/sched/fair.c:8543
Code: 5d 41 5e 41 5f 5d e9 ff 16 ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 81 ec 80 00 00 00 41
RSP: 0018:ffffc90000007ca0 EFLAGS: 00000046
RAX: 1ffffffff1bd7d65 RBX: 1ffff1100ef9a00d RCX: 5016c0cbb851bc00
RDX: 0000000000000008 RSI: 0000000000000000 RDI: ffff888077cd0000
RBP: ffff888077cd0000 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746
R10: dffffc0000000000 R11: ffffffff81949000 R12: dffffc0000000000
R13: 1ffff1100ef9a003 R14: ffffffff8debeb28 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881257a7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557318d5c8 CR3: 000000007871a000 CR4: 00000000003526f0
Call Trace:
select_task_rq kernel/sched/core.c:3607 [inline]
try_to_wake_up+0x4d8/0x12b0 kernel/sched/core.c:4316
hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:2013
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline]
RIP: 0010:vprintk_emit+0x49d/0x590 kernel/printk/printk.c:2422
Code: 0f 84 34 ff ff ff e8 72 9b 1f 00 fb eb 44 e8 6a 9b 1f 00 e8 15 12 eb 09 4d 85 f6 74 94 e8 5b 9b 1f 00 fb 48 c7 c7 60 08 53 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 6b 3b
RSP: 0018:ffffc9000460f7e0 EFLAGS: 00000293
RAX: ffffffff81a07015 RBX: ffffffff81a06e6e RCX: ffff88802cf00000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e530860
RBP: ffffc9000460f8f0 R08: ffffffff8fe53a37 R09: 1ffffffff1fca746
R10: dffffc0000000000 R11: fffffbfff1fca747 R12: 0000000000000000
R13: 0000000000000017 R14: 0000000000000200 R15: 1ffff920008c1f00
_printk+0xcf/0x120 kernel/printk/printk.c:2448
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_core_query+0x2c5/0x540 drivers/media/usb/dvb-usb/m920x.c:-1
dvb_usb_read_remote_control+0xb4/0x1a0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245