rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14565/1:b..l rcu: (detected by 1, t=10502 jiffies, g=58765, q=874516 ncpus=2) task:syz.7.1999 state:R running task stack:27544 pid:14565 tgid:14544 ppid:11412 task_flags:0x40044c flags:0x00080000 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:unwind_next_frame+0xbce/0x20b0 arch/x86/kernel/unwind_orc.c:605 Code: 03 4c 8b 44 24 28 80 3c 16 00 0f 85 e4 10 00 00 48 8b 14 24 49 89 45 48 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 a2 10 00 00 4c 89 e2 4d 89 75 38 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000516f1e0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff9121e614 RDX: 1ffff92000a2de51 RSI: 1ffff92000a2de53 RDI: ffffc9000516fc78 RBP: ffffc9000516f298 R08: ffffffff9121e618 R09: 000000001176973c R10: 0000000000000002 R11: 0000000000007d55 R12: ffffc9000516f2a0 R13: ffffc9000516f250 R14: ffffc9000516fc80 R15: ffffc9000516f284 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:165 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa22/0x1610 mm/page_alloc.c:3000 folios_put_refs+0x4be/0x750 mm/swap.c:1002 free_pages_and_swap_cache+0x245/0x4a0 mm/swap_state.c:355 __tlb_batch_free_encoded_pages+0xf9/0x290 mm/mmu_gather.c:136 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu mm/mmu_gather.c:404 [inline] tlb_finish_mmu+0x168/0x7c0 mm/mmu_gather.c:497 exit_mmap+0x3f9/0xb60 mm/mmap.c:1290 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x62/0x70 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x7d7/0x2bd0 kernel/exit.c:959 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+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: 0033:0x7f743a78f749 RSP: 002b:00007f743b6b30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f743a9e6098 RCX: 00007f743a78f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f743a9e6098 RBP: 00007f743a9e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f743a9e6128 R14: 00007ffcedcc8b90 R15: 00007ffcedcc8c78 rcu: rcu_preempt kthread starved for 10547 jiffies! g58765 f0x2 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:28192 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: CPU: 1 UID: 0 PID: 14572 Comm: syz.5.2007 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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 7a de 1e f6 48 89 df e8 32 31 1f f6 e8 ad f6 4b f6 fb bf 01 00 00 00 42 34 0f f6 65 8b 05 9b 99 37 08 85 c0 74 06 5b e9 01 4d 00 00 RSP: 0018:ffffc90005b07ca0 EFLAGS: 00000206 RAX: 0000000004e87d53 RBX: ffff888035d3d340 RCX: ffffffff81c70c3f RDX: 0000000000000000 RSI: ffffffff8dacea71 RDI: 0000000000000001 RBP: ffff888035d3d740 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9088b9d7 R11: ffff88807b430b30 R12: 0000000000000000 R13: 0000000000000021 R14: 0000000000000400 R15: ffff888035d3d340 FS: 00007f0d1ff136c0(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d1fed0800 CR3: 0000000031065000 CR4: 00000000003526f0 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1e6a/0x26d0 kernel/signal.c:3037 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: 0033:0x7f0d1ef8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0d1ff13038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: fffffffffffffe00 RBX: 00007f0d1f1e5fa0 RCX: 00007f0d1ef8f749 RDX: 0000000000000000 RSI: 0000000000002601 RDI: 0000200000000000 RBP: 00007f0d1f013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0d1f1e6038 R14: 00007f0d1f1e5fa0 R15: 00007ffea80ca528