INFO: task syz.2.1996:12080 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.2.1996 state:D stack:23440 pid:12080 tgid:12079 ppid:5828 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5282 [inline]
__schedule+0x14ed/0x5040 kernel/sched/core.c:6894
__schedule_loop kernel/sched/core.c:6976 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6991
io_schedule+0x80/0xd0 kernel/sched/core.c:7820
folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1170 [inline]
migrate_folio_unmap mm/migrate.c:1249 [inline]
migrate_pages_batch+0x14cd/0x35e0 mm/migrate.c:1890
migrate_pages_sync mm/migrate.c:2034 [inline]
migrate_pages+0x2006/0x28e0 mm/migrate.c:2116
compact_zone+0x25ba/0x4760 mm/compaction.c:2647
compact_node mm/compaction.c:2916 [inline]
compact_nodes mm/compaction.c:2938 [inline]
sysctl_compaction_handler+0x3a1/0x7b0 mm/compaction.c:2989
proc_sys_call_handler+0x4cb/0x700 fs/proc/proc_sysctl.c:600
iter_file_splice_write+0x972/0x10b0 fs/splice.c:738
do_splice_from fs/splice.c:938 [inline]
direct_splice_actor+0x101/0x160 fs/splice.c:1161
splice_direct_to_actor+0x5a8/0xcc0 fs/splice.c:1105
do_splice_direct_actor fs/splice.c:1204 [inline]
do_splice_direct+0x181/0x270 fs/splice.c:1230
do_sendfile+0x4da/0x7e0 fs/read_write.c:1370
__do_sys_sendfile64 fs/read_write.c:1425 [inline]
__se_sys_sendfile64+0xd9/0x190 fs/read_write.c:1417
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f928058f749
RSP: 002b:00007f9281374038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f92807e5fa0 RCX: 00007f928058f749
RDX: 00002000000000c0 RSI: 0000000000000003 RDI: 0000000000000004
RBP: 00007f9280613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92807e6038 R14: 00007f92807e5fa0 R15: 00007fff20412038
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e33efa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e33efa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e33efa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by klogd/5180:
#0: ffff8880b873ab98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:644
2 locks held by getty/5577:
#0: ffff88814eb3d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
5 locks held by kworker/1:5/5887:
#0: ffff888141ae2948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254
#1: ffffc9000453fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255
#2: ffff888144f0a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888144f0a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899
#3: ffff888026136198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff888026136198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
#4: ffff888031c07160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#4: ffff888031c07160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006
4 locks held by udevd/6190:
#0: ffff88808bfe82f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:183
#1: ffff888048767888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffff88805ec52878 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff88805ec52878 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173
#3: ffff888026136198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
#3: ffff888026136198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by udevd/6385:
#0: ffff888025b61358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by udevd/6386:
#0: ffff888025a33358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962
1 lock held by syz.2.1996/12080:
#0: ffff88807c89a420 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1160
=============================================
NMI backtrace for cpu 0
CPU: 0 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 10/25/2025
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:161 [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:375 [inline]
watchdog+0xe88/0xee0 kernel/hung_task.c:588
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 36 Comm: kworker/1:1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 8e ac 9b fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf 87 02 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000ac7470 EFLAGS: 00000002
RAX: 1ffffffff340da00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff9a06d590 R08: ffff888024ca0237 R09: 1ffff11004994046
R10: dffffc0000000000 R11: ffffffff85254df0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a06d300 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125abd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe37b7b6ad8 CR3: 00000000758a8000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x1301/0x1b60 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3131 [inline]
console_flush_one_record kernel/printk/printk.c:3217 [inline]
console_flush_all+0x713/0xb00 kernel/printk/printk.c:3291
__console_flush_and_unlock kernel/printk/printk.c:3321 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3361
vprintk_emit+0x47b/0x550 kernel/printk/printk.c:2428
_printk+0xcf/0x120 kernel/printk/printk.c:2453
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query+0x2f6/0x830 drivers/media/usb/dvb-usb/m920x.c:-1
legacy_dvb_usb_read_remote_control+0x100/0x470 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443
kthread+0x389/0x480 kernel/kthread.c:467
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246