INFO: task syz.4.1554:13077 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.4.1554 state:D stack:24184 pid:13077 tgid:13065 ppid:5805 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 io_schedule+0x8a/0xf0 kernel/sched/core.c:7832 folio_wait_bit_common+0x414/0xa70 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1170 [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: 0033:0x7fb0f599c799 RSP: 002b:00007fb0f68a4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fb0f5c16270 RCX: 00007fb0f599c799 RDX: 00002000000000c0 RSI: 0000000000000009 RDI: 000000000000000b RBP: 00007fb0f5a32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb0f5c16308 R14: 00007fb0f5c16270 R15: 00007fff38f2bba8 Showing all locks held in the system: 2 locks held by kworker/u8:1/13: 3 locks held by kworker/1:0/24: #0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900001e7d08 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffffffff8e7f31f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by khungtaskd/31: #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e75e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:6/531: 2 locks held by kworker/u8:9/4592: #0: ffff88801ef1d948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000f9ffd08 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 2 locks held by getty/5568: #0: ffff888038c200a0 (&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 1 lock held by udevd/11936: #0: ffff8880272e4358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 1 lock held by syz.4.1554/13077: #0: ffff888036366420 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 2 locks held by syz.6.1858/14446: #0: ffff888059752488 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff888059752488 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x86/0x260 net/socket.c:661 #1: ffffffff8e7f31f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz.2.1866/14484: #0: ffff8880591840e0 (&type->s_umount_key#72/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd20 fs/super.c:345 4 locks held by syz.3.1867/14488: ============================================= 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 02/12/2026 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: 5867 Comm: kworker/0:5 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: rcu_gp process_srcu RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:__lock_acquire+0xdad/0x2630 kernel/locking/lockdep.c:5233 Code: ff ff ff ff c7 44 24 08 01 00 00 00 41 b8 ff ff ff ff e9 81 f7 ff ff 0f b7 43 f8 66 25 ff 1f 0f b7 c0 48 0f a3 05 f3 ec 2f 14 <0f> 83 e1 02 00 00 48 8d 04 80 48 8d 04 80 48 8d 04 c5 a0 bb 14 96 RSP: 0018:ffffc90002f37980 EFLAGS: 00000003 RAX: 000000000000004a RBX: ffff88802d3c30b8 RCX: 0000000000000004 RDX: 0000000097b38c42 RSI: 00000000f4d76a99 RDI: 0000000071237a96 RBP: ffff88802d3c24c0 R08: 000000007c4c0ffd R09: 000000000000001e R10: 0000000000000004 R11: 0000000000000000 R12: 0000000000000000 R13: 000000000000001e R14: 0000000000000004 R15: 313aa66297b38c42 FS: 0000000000000000(0000) GS:ffff888124342000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f36629e7158 CR3: 0000000078d88000 CR4: 00000000003526f0 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_sched include/linux/rcupdate.h:948 [inline] pfn_valid include/linux/mmzone.h:2197 [inline] __virt_addr_valid+0x224/0x620 arch/x86/mm/physaddr.c:54 kasan_addr_to_slab+0xd/0x50 mm/kasan/common.c:47 kasan_record_aux_stack+0xe/0xc0 mm/kasan/generic.c:541 insert_work+0x36/0x230 kernel/workqueue.c:2199 __queue_work+0x9bc/0x1150 kernel/workqueue.c:2354 __queue_delayed_work+0x365/0x470 kernel/workqueue.c:2522 queue_delayed_work_on+0x180/0x1e0 kernel/workqueue.c:2574 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