INFO: task syz.7.6049:31587 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.7.6049 state:D stack:25440 pid:31587 tgid:31584 ppid:28823 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
io_schedule+0x8a/0xf0 kernel/sched/core.c:7835
folio_wait_bit_common+0x414/0xa70 mm/filemap.c:1323
folio_lock include/linux/pagemap.h:1159 [inline]
migrate_folio_unmap mm/migrate.c:1250 [inline]
migrate_pages_batch+0x1b85/0x4530 mm/migrate.c:1890
migrate_pages_sync+0x4db/0x880 mm/migrate.c:2034
migrate_pages+0x1aae/0x28a0 mm/migrate.c:2116
compact_zone+0x2464/0x44c0 mm/compaction.c:2647
compact_node+0x17f/0x2c0 mm/compaction.c:2916
compact_nodes mm/compaction.c:2938 [inline]
sysctl_compaction_handler mm/compaction.c:2989 [inline]
sysctl_compaction_handler+0x141/0x210 mm/compaction.c:2976
proc_sys_call_handler+0x47f/0x5a0 fs/proc/proc_sysctl.c:600
iter_file_splice_write+0x830/0x10a0 fs/splice.c:736
do_splice_from fs/splice.c:936 [inline]
direct_splice_actor+0x192/0x6c0 fs/splice.c:1159
splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x174/0x240 fs/splice.c:1228
do_sendfile+0xadc/0xe20 fs/read_write.c:1372
__do_sys_sendfile64 fs/read_write.c:1427 [inline]
__se_sys_sendfile64 fs/read_write.c:1419 [inline]
__x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1419
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f588c79c819
RSP: 002b:00007f588d614028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f588ca16090 RCX: 00007f588c79c819
RDX: 00002000000000c0 RSI: 0000000000000006 RDI: 0000000000000007
RBP: 00007f588c832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000
R13: 00007f588ca16128 R14: 00007f588ca16090 R15: 00007ffda5fb1c38
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8e7f3478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by khungtaskd/31:
#0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5562:
#0: ffff8880390c20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:7/5961:
#0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc9000486fd08 ((work_completion)(&tn->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: tipc_net_finalize_work+0x13/0x90 net/tipc/net.c:148
2 locks held by kworker/0:4/19175:
4 locks held by kworker/u8:6/20229:
#0: ffff88801cac9148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc900045efd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffffffff905fbc10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:675
#3: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: cfg802154_pernet_exit+0x17/0xe0 net/ieee802154/core.c:351
2 locks held by kworker/u8:11/21947:
3 locks held by kworker/u8:18/21949:
#0: ffff88813fea4148
((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc9000548fd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
2 locks held by kworker/u8:38/22598:
#0: ffff88801e32e148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc900054bfd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
1 lock held by udevd/29686:
#0: ffff888027969358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
3 locks held by kworker/0:5/31506:
#0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251
#1: ffffc90004ba7d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252
#2: ffffffff8e7f3478 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
1 lock held by syz.7.6049/31587:
#0: ffff888053686420 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
1 lock held by syz.6.6436/691:
#0: ffff888027969358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
1 lock held by syz.6.6436/692:
#0: ffff888027969358 (&disk->open_mutex){+.+.}-{4:4}
, at: sync_bdevs+0x153/0x480 block/bdev.c:1304
1 lock held by syz.9.6595/1303:
#0: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
4 locks held by syz.5.6598/1310:
#0: ffff88803d8b4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff88803d8b40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908ad748 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908ad748 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
#3: ffff888041ff1b00 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777
1 lock held by syz.8.6599/1320:
1 lock held by syz.4.6601/1327:
#0: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90614468 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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: 19175 Comm: kworker/0:4 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: events legacy_dvb_usb_read_remote_control
RIP: 0010:__lock_acquire+0x122/0x2630 kernel/locking/lockdep.c:5170
Code: 01 48 89 04 24 75 1f 48 8d b4 1d 30 0b 00 00 0f b7 46 20 25 ff 1f 00 00 44 39 e8 75 09 4d 85 e4 0f 85 99 05 00 00 48 8b 04 24 <44> 89 ea 66 81 e2 ff 1f 48 01 c3 0f b7 43 20 4c 89 53 10 4c 89 63
RSP: 0018:ffffc90000007878 EFLAGS: 00000016
RAX: ffff8880367ed4d8 RBX: 0000000000000078 RCX: 0000000000000003
RDX: 0000000000000000 RSI: ffff8880367ed528 RDI: ffffffff8e7e7920
RBP: ffff8880367ec980 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff8e7e7920 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000007 R14: 0000000000000002 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124338000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 0000000027a02000 CR4: 00000000003526f0
DR0: 0000000000000001 DR1: 0000000000000c5d DR2: 0000000000000009
DR3: 0000000000000a25 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kmem_cache_free+0x124/0x6a0 mm/slub.c:6295
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x553/0x6b0 kernel/printk/printk.c:2478
Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 c8 2d 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 96 28 21 00 48 85 ed 0f 85 27 01 00 00 a8 2d 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc9000503f9c8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000017 RCX: ffffffff81e7caca
RDX: ffff8880367ec980 RSI: ffffffff81e7cad4 RDI: ffff8880367ec980
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000a07f3b
R13: 0000000000000200 R14: ffff88801eef8000 R15: ffffc9000503fa90
_printk+0xcf/0x110 kernel/printk/printk.c:2504
m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline]
m920x_rc_query.cold+0x2b/0x30 drivers/media/usb/dvb-usb/m920x.c:188
legacy_dvb_usb_read_remote_control+0x10c/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245