INFO: task syz.1.1797:11427 blocked in I/O wait for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1797 state:D stack:24576 pid:11427 tgid:11426 ppid:5614 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7231 __schedule_loop kernel/sched/core.c:7308 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7323 io_schedule+0x7f/0xd0 kernel/sched/core.c:8151 folio_wait_bit_common+0x83c/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1157 [inline] migrate_folio_unmap mm/migrate.c:1249 [inline] migrate_pages_batch+0x1baa/0x43d0 mm/migrate.c:1907 migrate_pages_sync mm/migrate.c:2051 [inline] migrate_pages+0x1f90/0x2900 mm/migrate.c:2133 compact_zone+0x3144/0x4a70 mm/compaction.c:2668 compact_node mm/compaction.c:2937 [inline] compact_nodes mm/compaction.c:2959 [inline] sysctl_compaction_handler+0x3f3/0x880 mm/compaction.c:3010 proc_sys_call_handler+0x4c7/0x830 fs/proc/proc_sysctl.c:600 iter_file_splice_write+0xa36/0x1240 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x104/0x160 fs/splice.c:1159 splice_direct_to_actor+0x586/0xcc0 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x19b/0x2a0 fs/splice.c:1228 do_sendfile+0x540/0x7e0 fs/read_write.c:1371 __do_sys_sendfile64 fs/read_write.c:1426 [inline] __se_sys_sendfile64+0xdf/0x1a0 fs/read_write.c:1418 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efee40ade59 RSP: 002b:00007efee2306028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007efee4335fa0 RCX: 00007efee40ade59 RDX: 00002000000000c0 RSI: 0000000000000007 RDI: 0000000000000008 RBP: 00007efee4143e6f R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000 R13: 00007efee4336038 R14: 00007efee4335fa0 R15: 00007fffc0c8c218 Showing all locks held in the system: 3 locks held by kworker/0:1/11: #0: ffff88801af23138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801af23138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801af23138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90000107c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90000107c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90000107c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffff888027fa6210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888027fa6210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899 1 lock held by khungtaskd/38: #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6821 3 locks held by kworker/0:1H/139: #0: ffff88813fe1b538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88813fe1b538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88813fe1b538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc9000154fc60 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc9000154fc60 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc9000154fc60 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 3 locks held by kworker/0:2/198: #0: ffff88813fe1a538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88813fe1a538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88813fe1a538 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90003b0fc60 ((gc_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90003b0fc60 ((gc_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90003b0fc60 ((gc_work).work){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 2 locks held by udevd/4969: #0: ffffffff8e935f38 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #0: ffffffff8e935f38 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #0: ffffffff8e935f38 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8e935f38 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_check_open_permission+0x1d3/0x470 security/tomoyo/file.c:772 #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 2 locks held by getty/5359: #0: ffff8880367e60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5590: #0: ffff88802c477198 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88802c477198 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1450 1 lock held by udevd/5796: #0: ffff8880279304c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd00 block/bdev.c:991 5 locks held by syz-executor/9500: #0: ffff8880568ca478 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff8880568ca478 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:738 #1: ffff88803a038358 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #1: ffff88803a038358 (sk_lock-AF_INET6){+.+.}-{0:0}, at: tcp_close+0x1d/0x110 net/ipv4/tcp.c:3310 #2: ffffffff8e0592e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_write_lock+0x86/0x220 kernel/locking/spinlock_rt.c:261 1 lock held by syz.1.1797/11427: #0: ffff888035eaa510 (sb_writers#3){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1158 3 locks held by syz.5.2506/13499: #0: ffff88802ad3acb0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88802ad3acb0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1284 #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290 #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #2: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: eb 6f 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 3c 26 00 fb f4 cc cf 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc900001e7e40 EFLAGS: 00000246 RAX: 0000000000e4d2f9 RBX: ffffffff81994540 RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d87e102 RDI: ffffffff8bca5e80 RBP: ffffc900001e7f10 R08: ffff8880b8733d5b R09: 1ffff110170e67ab R10: dffffc0000000000 R11: ffffed10170e67ac R12: 0000000000000000 R13: 1ffff11003bd8ba0 R14: 1ffff9200003cfd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d49000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555925ca48 CR3: 00000000258da000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x157