INFO: task syz.1.5727:27818 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.1.5727 state:D stack:25616 pid:27818 tgid:27815 ppid:18408 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: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: 0033:0x7fa44e79c799 RSP: 002b:00007fa44c9f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fa44ea16090 RCX: 00007fa44e79c799 RDX: 00002000000000c0 RSI: 000000000000000b RDI: 000000000000000c RBP: 00007fa44e832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa44ea16128 R14: 00007fa44ea16090 R15: 00007fff050cd1d8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7e78e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e78e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e78e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5567: #0: ffff888039e790a0 (&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/0:5/5869: #0: ffff88813fe67148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90004127d08 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88805ca92240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1b8/0x63b0 drivers/net/netdevsim/fib.c:1490 1 lock held by udevd/21143: #0: ffff888028153358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 1 lock held by syz.1.5727/27818: #0: ffff88802ac32420 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 1 lock held by dhcpcd-run-hook/32135: ============================================= 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 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32139 Comm: sed Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__rcu_read_unlock+0xa7/0x5e0 kernel/rcu/tree_plugin.h:441 Code: da 01 00 00 8b 83 c8 04 00 00 85 c0 75 51 48 8d bb c4 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 8b 01 00 00 8b RSP: 0018:ffffc90003d37380 EFLAGS: 00000a07 RAX: dffffc0000000000 RBX: ffff8880563e24c0 RCX: ffffc90003d3737c RDX: 0000000000000000 RSI: ffffffff8de5278d RDI: ffff8880563e2984 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000015d45 R12: ffffc90003d37478 R13: ffffc90003d37428 R14: ffffc90003d37d98 R15: ffffc90003d3745c FS: 0000000000000000(0000) GS:ffff88812443f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7aaca70368 CR3: 000000000e598000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:883 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x3c8/0x1ea0 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 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xaea/0x1790 mm/page_alloc.c:3040 folios_put_refs+0x53c/0x840 mm/swap.c:1002 free_pages_and_swap_cache+0x242/0x480 mm/swap_state.c:423 __tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:138 tlb_batch_pages_flush mm/mmu_gather.c:151 [inline] tlb_flush_mmu_free mm/mmu_gather.c:398 [inline] tlb_flush_mmu mm/mmu_gather.c:405 [inline] tlb_finish_mmu+0x1b0/0x810 mm/mmu_gather.c:530 exit_mmap+0x454/0xa30 mm/mmap.c:1315 __mmput+0x12a/0x410 kernel/fork.c:1175 mmput+0x67/0x80 kernel/fork.c:1198 exit_mm kernel/exit.c:581 [inline] do_exit+0x819/0x2b60 kernel/exit.c:964 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118 __do_sys_exit_group kernel/exit.c:1129 [inline] __se_sys_exit_group kernel/exit.c:1127 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1127 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f29e21116c5 Code: Unable to access opcode bytes at 0x7f29e211169b. RSP: 002b:00007ffef38551d8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f29e2212fe8 RCX: 00007f29e21116c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f29e2211680 R15: 00007f29e2213000