rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P24/1:b..l P5848/1:b..l P5492/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9949, q=96 ncpus=2) task:dhcpcd state:R running task stack:21208 pid:5492 tgid:5492 ppid:5491 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193 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:orc_find arch/x86/kernel/unwind_orc.c:228 [inline] RIP: 0010:unwind_next_frame+0x214/0x23d0 arch/x86/kernel/unwind_orc.c:510 Code: ef 08 8b 15 6e 62 47 0c 8d 42 ff 44 39 f8 0f 86 78 04 00 00 44 89 f8 4c 8d 2c 85 64 3b e1 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 2c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d RSP: 0018:ffffc90003a07258 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 168621e804c97500 RDX: 00000000000a617e RSI: ffffffff8be07940 RDI: ffffffff8be07900 RBP: dffffc0000000000 R08: ffffffff81742f85 R09: ffffffff8e13f2e0 R10: ffffc90003a07378 R11: ffffffff81ad9d50 R12: ffffffff82174780 R13: ffffffff90e59880 R14: ffffc90003a07328 R15: 0000000000011747 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] __kmalloc_cache_node_noprof+0x475/0x700 mm/slub.c:5792 kmalloc_node_noprof include/linux/slab.h:983 [inline] __get_vm_area_node+0x13f/0x300 mm/vmalloc.c:3246 __vmalloc_node_range_noprof+0x371/0x16a0 mm/vmalloc.c:4049 __vmalloc_node_noprof+0xc2/0x110 mm/vmalloc.c:4149 alloc_thread_stack_node kernel/fork.c:359 [inline] dup_task_struct+0x228/0x9a0 kernel/fork.c:926 copy_process+0x4ea/0x3950 kernel/fork.c:2056 kernel_clone+0x21e/0x820 kernel/fork.c:2655 __do_sys_clone kernel/fork.c:2796 [inline] __se_sys_clone kernel/fork.c:2780 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2780 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fab01913636 RSP: 002b:00007ffef1047080 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffef1047088 RCX: 00007fab01913636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffef10675d0 R08: 0000000000000000 R09: 0000000000000001 R10: 00007fab0183fa10 R11: 0000000000000246 R12: 00007ffef10471c0 R13: 0000000000000000 R14: 0000000000000000 R15: 00005556f2e2eac0 task:dhcpcd state:R running task stack:25432 pid:5848 tgid:5848 ppid:5492 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:debug_lockdep_rcu_enabled+0x16/0x40 kernel/rcu/update.c:320 Code: cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 17 78 44 04 00 74 1e 83 3d 2a a7 44 04 00 <74> 15 65 48 8b 0c 25 08 b0 9f 92 31 c0 83 b9 2c 0b 00 00 00 0f 94 RSP: 0018:ffffc900041af090 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffffff90dc8c01 RCX: ffffc900041aff50 RDX: ffffc900041af101 RSI: dffffc0000000000 RDI: ffffc900041af170 RBP: dffffc0000000000 R08: ffffc900041aff38 R09: 0000000000000000 R10: ffffc900041af1b8 R11: fffff52000835e39 R12: ffffc900041aff48 R13: ffffc900041a8000 R14: ffffc900041af168 R15: ffffffff81742f85 rcu_read_unlock include/linux/rcupdate.h:895 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x1a64/0x23d0 arch/x86/kernel/unwind_orc.c:695 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3119 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3239 slab_free_hook mm/slub.c:2504 [inline] slab_free mm/slub.c:6674 [inline] kmem_cache_free+0x488/0x620 mm/slub.c:6785 anon_vma_free mm/rmap.c:136 [inline] __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2777 put_anon_vma include/linux/rmap.h:117 [inline] unlink_anon_vmas+0x503/0x670 mm/rmap.c:443 free_pgtables+0x737/0x9d0 mm/memory.c:414 vms_clear_ptes+0x5ac/0x7c0 mm/vma.c:1236 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1280 do_vmi_align_munmap+0x364/0x440 mm/vma.c:1539 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1587 __vm_munmap+0x207/0x380 mm/vma.c:3203 __do_sys_munmap mm/mmap.c:1077 [inline] __se_sys_munmap mm/mmap.c:1074 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1074 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fab01a4e2e7 RSP: 002b:00007ffef1046e98 EFLAGS: 00000202 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 000055570ec68960 RCX: 00007fab01a4e2e7 RDX: 0000000000000001 RSI: 0000000000029910 RDI: 00007fab01810000 RBP: 00007ffef1046fa0 R08: 00000000000004f0 R09: 0000000000000002 R10: 00007ffef1046dd0 R11: 0000000000000202 R12: 00007ffef1046ed8 R13: 00007fab01a61000 R14: 000055570ec68960 R15: 0000000000000000 task:kworker/1:0 state:R running task stack:24120 pid:24 tgid:24 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7143 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752 rcu_read_unlock include/linux/rcupdate.h:895 [inline] gc_worker+0xb36/0x1380 net/netfilter/nf_conntrack_core.c:1617 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9f5/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: rcu_preempt kthread starved for 10613 jiffies! g9949 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27728 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 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+0x599/0xb30 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: 0 UID: 0 PID: 0 Comm: swapper/0 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+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc 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 33 9e 2a 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: 7a55bed98eefd900 RBX: ffffffff819786ba RCX: 7a55bed98eefd900 RDX: 0000000000000001 RSI: ffffffff8d997e54 RDI: ffffffff8be07960 RBP: ffffffff8de07ea8 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fa22f70 R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f73247aa0f0 CR3: 000000007c292000 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:758 start_kernel+0x3ac/0x400 init/main.c:1208 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147