rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11339/1:b..l rcu: (detected by 0, t=10502 jiffies, g=43377, q=390 ncpus=2) task:syz.0.1291 state:R running task stack:23624 pid:11339 tgid:11339 ppid:5812 task_flags:0x40064c flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5945 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 5c f0 3a 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 87 2c 03 00 45 31 ed eb RSP: 0018:ffffc9000e057128 EFLAGS: 00000286 RAX: 0000000000000046 RBX: ffff888058f954b0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8daa7ab3 RDI: ffffffff8bf2b300 RBP: ffffffff8e3c9620 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000001000 R11: ffff888058f954b0 R12: ffff888058f94980 R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000000 lookup_page_ext+0x6e/0x100 mm/page_ext.c:254 page_ext_iter_begin include/linux/page_ext.h:132 [inline] __update_page_owner_free_handle.constprop.0+0xaa/0x4a0 mm/page_owner.c:284 __reset_page_owner+0x93/0x1a0 mm/page_owner.c:321 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000 folios_put_refs+0x4be/0x750 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x58f/0x1140 mm/shmem.c:1137 shmem_truncate_range mm/shmem.c:1249 [inline] shmem_evict_inode+0x39e/0xbe0 mm/shmem.c:1379 evict+0x3c2/0xad0 fs/inode.c:837 iput_final fs/inode.c:1951 [inline] iput.part.0+0x621/0x1190 fs/inode.c:2003 iput+0x35/0x40 fs/inode.c:1966 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:467 __dentry_kill+0x1d0/0x600 fs/dcache.c:670 finish_dput+0x76/0x480 fs/dcache.c:879 dput.part.0+0x451/0x570 fs/dcache.c:928 dput+0x1f/0x30 fs/dcache.c:920 __fput+0x51c/0xb70 fs/file_table.c:476 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x87f/0x2bd0 kernel/exit.c:971 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x38a/0x8c0 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f55f8b8f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f55f8de6180 RCX: 00007f55f8b8f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007f55f8c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f55f8de6218 R14: 00007f55f8de6180 R15: 00007ffd9121c998 rcu: rcu_preempt kthread starved for 10539 jiffies! g43377 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28440 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11472 Comm: syz.3.1334 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x66/0x70 kernel/kcov.c:235 Code: 82 48 16 00 00 83 f8 02 75 20 48 8b 8a 50 16 00 00 8b 92 4c 16 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000d7a7ae0 EFLAGS: 00000093 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff81aadc4c RDX: ffff888058dc24c0 RSI: ffffffff81aae072 RDI: ffffffff8dd7af28 RBP: ffff8880b8528440 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888058dc2ff0 R12: 0000000000000001 R13: ffff88807451b518 R14: 0000000000000000 R15: ffff8880b85284c0 FS: 0000555573eb5500(0000) GS:ffff8881249f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f22d0008190 CR3: 0000000030435000 CR4: 00000000003526f0 Call Trace: __hrtimer_start_range_ns kernel/time/hrtimer.c:1263 [inline] hrtimer_start_range_ns+0x962/0x11f0 kernel/time/hrtimer.c:1322 __posixtimer_deliver_signal kernel/time/posix-timers.c:321 [inline] posixtimer_deliver_signal+0x30d/0x6b0 kernel/time/posix-timers.c:347 dequeue_signal+0x307/0x520 kernel/signal.c:660 get_signal+0x601/0x26d0 kernel/signal.c:2914 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f94dec6efbb Code: 03 14 ca 80 3d 0d 8e 37 00 00 49 89 d6 48 89 d5 74 28 25 ff 0f 00 00 83 f0 3d 8d 04 c0 89 c5 c1 ed 04 31 c5 69 ed 2d eb d4 27 <89> e8 c1 e8 0f 31 c5 81 e5 ff 0f 00 00 48 31 d5 80 3d 76 30 37 00 RSP: 002b:00007fff1c9ec410 EFLAGS: 00000a07 RAX: 000000000000034e RBX: 00007f94dfb15720 RCX: 000000000000122b RDX: ffffffff8162306f RSI: ffffffff81623034 RDI: 0000000000000009 RBP: 000000007a399a72 R08: 00007f94defe6038 R09: 00007f94defd2000 R10: 00007f94de7ff008 R11: 0000000000000009 R12: 0000000000000009 R13: 0000000000000000 R14: ffffffff8162306f R15: 000000000000122b