rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5960/1:b..l P5953/1:b..l rcu: (detected by 0, t=10502 jiffies, g=8065, q=370 ncpus=2) task:kworker/1:9 state:R running task stack:23704 pid:5953 tgid:5953 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker 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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x183/0x2d0 kernel/locking/lockdep.c:5893 Code: 0f c1 05 48 01 19 12 83 f8 01 0f 85 03 01 00 00 9c 58 f6 c4 02 0f 85 ee 00 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 dd b9 18 12 0f 85 32 01 00 00 48 83 c4 18 5b 41 5c 41 RSP: 0018:ffffc90002fd7a90 EFLAGS: 00000206 RAX: 68c6c5ea27bed900 RBX: ffffffff8e3c96a0 RCX: ffffc90002fd7a9c RDX: 0000000000000002 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400 RBP: ffffffff9b0a38ac R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff888035cdaff0 R12: ffffffff89940a39 R13: 0000000000000206 R14: ffff888035cda4c0 R15: 0000000000000003 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] gc_worker+0x99e/0x16e0 net/netfilter/nf_conntrack_core.c:1617 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 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 task:syz-executor248 state:R running task stack:28792 pid:5960 tgid:5960 ppid:5833 task_flags:0x400040 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:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: b4 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 72 b9 ee 0e 0f 82 74 02 00 00 8b 35 0a ea ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 89 b4 18 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc90003097570 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c96a0 RCX: 000000007a0f8404 RDX: 0000000000000000 RSI: ffffffff8daa7ea1 RDI: ffffffff8bf2b400 RBP: 0000000000000002 R08: 0000000077c9b173 R09: 00000000377c9b17 R10: 0000000000000002 R11: ffff888031f38b30 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_noprof+0x33d/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822 tomoyo_path_symlink+0x97/0xe0 security/tomoyo/tomoyo.c:212 security_path_symlink+0x152/0x2e0 security/security.c:1476 do_symlinkat+0x126/0x4b0 fs/namei.c:5539 __do_sys_symlink fs/namei.c:5567 [inline] __se_sys_symlink fs/namei.c:5565 [inline] __x64_sys_symlink+0x75/0x90 fs/namei.c:5565 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcd12c779b7 RSP: 002b:00007ffdcf644ef8 EFLAGS: 00000206 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fcd12c779b7 RDX: 0000000000000009 RSI: 00007fcd12cc604e RDI: 00007fcd12cc6059 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007fcd12cc64e1 R13: 0000000000000003 R14: 00007ffdcf644f30 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10567 jiffies! g8065 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:28328 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: c6 5f 02 c3 cc cc cc cc 0f 1f 00 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 13 49 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6 RAX: 00000000000ee8a3 RBX: 0000000000000001 RCX: ffffffff8b7816d9 RDX: 0000000000000000 RSI: ffffffff8dacdf23 RDI: ffffffff8bf2b400 RBP: ffffed1003b57498 R08: 0000000000000001 R09: ffffed10170a673d R10: ffff8880b85339eb R11: ffff88801dabaff0 R12: 0000000000000001 R13: ffff88801daba4c0 R14: ffffffff9088b4d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcd12c9f150 CR3: 000000007bae7000 CR4: 00000000003526f0 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+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148