rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8878/1:b..l rcu: (detected by 0, t=10502 jiffies, g=49633, q=492 ncpus=2) task:syz-executor state:R running task stack:21592 pid:8878 tgid:8878 ppid:8870 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline] RIP: 0010:unwind_next_frame+0x1a64/0x23d0 arch/x86/kernel/unwind_orc.c:695 Code: 00 00 c6 03 01 4c 8b 7c 24 50 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 35 02 00 00 41 c7 06 00 00 00 00 31 db e8 4c 7f e5 09 <85> c0 74 3a e8 53 e5 32 00 84 c0 75 31 e8 3a 7f e5 09 85 c0 74 28 RSP: 0018:ffffc9000ba47518 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffff9046cf01 RCX: ffff88801c3abd00 RDX: ffffc9000ba47601 RSI: dffffc0000000000 RDI: ffffc9000ba475f0 RBP: dffffc0000000000 R08: ffffc9000ba47d80 R09: ffffc9000ba47638 R10: dffffc0000000000 R11: fffff52001748ec9 R12: ffffc9000ba47d90 R13: ffffc9000ba40000 R14: ffffc9000ba475e8 R15: ffffffff8173fd65 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_noprof+0x41d/0x800 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] tomoyo_realpath_from_path+0xe3/0x5d0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 tomoyo_path_rmdir+0xa2/0xe0 security/tomoyo/tomoyo.c:195 security_path_rmdir+0x167/0x360 security/security.c:1441 do_rmdir+0x1fb/0x4a0 fs/namei.c:5288 __do_sys_unlinkat fs/namei.c:5468 [inline] __se_sys_unlinkat fs/namei.c:5462 [inline] __x64_sys_unlinkat+0xc2/0xf0 fs/namei.c:5462 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4c9ed8ed27 RSP: 002b:00007ffe831b9058 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f4c9ed8ed27 RDX: 0000000000000200 RSI: 00007ffe831ba1a0 RDI: 00000000ffffff9c RBP: 00007f4c9ee13d7d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffe831ba1a0 R13: 00007f4c9ee13d7d R14: 0000000000083342 R15: 00007ffe831ba1e0 rcu: rcu_preempt kthread starved for 10545 jiffies! g49633 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:27776 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 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: 0 Comm: swapper/1 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:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 3e b4 b6 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 c1 0e 00 f3 0f 1e fa fb f4 13 b4 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2 RAX: 000000000061f293 RBX: ffffffff819713ee RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d79207b RDI: ffffffff8bc083e0 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822270 R13: 1ffff1100385eb70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000026000 CR3: 0000000059f33000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147