rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4188/1:b..l (detected by 0, t=10502 jiffies, g=20981, q=494) task:syz-executor state:R running task stack:22192 pid: 4188 ppid: 4181 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:bpf_tree_comp kernel/bpf/core.c:610 [inline] RIP: 0010:__lt_find include/linux/rbtree_latch.h:115 [inline] RIP: 0010:latch_tree_find include/linux/rbtree_latch.h:208 [inline] RIP: 0010:bpf_ksym_find kernel/bpf/core.c:692 [inline] RIP: 0010:is_bpf_text_address+0x109/0x270 kernel/bpf/core.c:726 Code: e7 03 47 8d 2c 7f 49 f7 dd 4f 8d bc 2e 60 ff ff ff 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 da 02 39 00 4d 8b 3f <4c> 89 ff 48 89 de e8 ec e1 f3 ff 49 39 df 76 0c e8 02 e0 f3 ff b8 RSP: 0018:ffffc90002f1f340 EFLAGS: 00000246 RAX: 1ffffffff1a89f16 RBX: 00007f0945d2f1c7 RCX: ffff88807da6d940 RDX: 0000000000000000 RSI: ffffffff8a7a41e0 RDI: ffffffff8a7a41a0 RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff203dc18 R10: dffffc0000000000 R11: fffffbfff203dc19 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff8d44f950 R15: ffffffffa001a000 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 save_stack+0x121/0x230 mm/page_owner.c:119 __reset_page_owner+0x51/0x180 mm/page_owner.c:140 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page_list+0x119/0x830 mm/page_alloc.c:3433 release_pages+0x185f/0x1bd0 mm/swap.c:963 __pagevec_release+0x6d/0xe0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x5cd/0x19a0 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x1e2/0x9a0 mm/shmem.c:1145 evict+0x4b6/0x8b0 fs/inode.c:647 do_unlinkat+0x3e7/0x710 fs/namei.c:4363 __do_sys_unlink fs/namei.c:4404 [inline] __se_sys_unlink fs/namei.c:4402 [inline] __x64_sys_unlink+0x45/0x50 fs/namei.c:4402 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f0945d2f1c7 RSP: 002b:00007ffcf3ec8908 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0945d2f1c7 RDX: 00007ffcf3ec8930 RSI: 00007ffcf3ec89c0 RDI: 00007ffcf3ec89c0 RBP: 00007ffcf3ec89c0 R08: 00007ffcf3ec99c0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffcf3ec9a50 R13: 00007f0945dc6474 R14: 000000000002e1aa R15: 00007ffcf3ec9a90 rcu: rcu_preempt kthread starved for 2079 jiffies! g20981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 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:I stack:27440 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:should_failslab+0x0/0x20 mm/slab_common.c:1350 Code: 84 c0 74 1b 48 89 df e8 0e ce 13 00 49 89 c6 48 89 df 48 89 c6 e8 d0 3f 14 00 4c 89 f0 eb 02 31 c0 5b 41 5e c3 31 c0 c3 66 90 db 73 14 00 31 c9 84 c0 b8 f4 ff ff ff 0f 44 c1 c3 66 2e 0f 1f RSP: 0018:ffffc90000d479b8 EFLAGS: 00000246 RAX: 0000000000208040 RBX: ffff888016c4f8c0 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 0000000000002120 RDI: ffff888016c4f8c0 RBP: 0000000000002120 R08: 0000000000000038 R09: ffff88804b69ebd0 R10: 0000000000000003 R11: 0000000017af8faa R12: f8f8f8f8f8f8f8f8 R13: ffffc90000d47be0 R14: ffffc90000d479f0 R15: 0000000000000001 slab_pre_alloc_hook+0x51/0xc0 mm/slab.h:494 slab_alloc_node mm/slub.c:3139 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x3d/0x280 mm/slub.c:3238 kmem_cache_zalloc include/linux/slab.h:728 [inline] fill_pool lib/debugobjects.c:172 [inline] __debug_object_init+0x819/0xc80 lib/debugobjects.c:615 init_timer_on_stack_key kernel/time/timer.c:752 [inline] schedule_timeout+0x12d/0x2d0 kernel/time/timer.c:2115 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 5928 Comm: syz.5.404 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x1110/0x1270 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x845/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline] RIP: 0010:syscall_enter_from_user_mode+0x2a/0x70 kernel/entry/common.c:114 Code: 41 56 53 48 89 f3 49 89 fe 48 8b 7c 24 10 e8 3d f6 ff ff eb 31 eb 35 e8 24 05 bf f7 e8 1f 03 bf f7 fb 65 48 8b 05 f6 4f 42 76 <48> 8b 70 08 40 f6 c6 3f 74 0b 4c 89 f7 5b 41 5e e9 a1 00 a7 f7 48 RSP: 0018:ffffc9000344ff08 EFLAGS: 00000286 RAX: ffff888022b55940 RBX: 00000000000000ca RCX: dec97ff76221da00 RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4200 RBP: ffffc9000344ff48 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd R10: dffffc0000000000 R11: fffffbfff1b161be R12: 0000000000000000 R13: 0000000000000000 R14: ffffc9000344ff58 R15: 0000000000000000 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe4b50c50d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe4b331d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fe4b534cfa8 RCX: 00007fe4b50c50d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fe4b534cfa8 RBP: 00007fe4b534cfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe4b534d038 R14: 00007ffcbeeaf3b0 R15: 00007ffcbeeaf498