rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8217/1:b..l rcu: (detected by 1, t=10502 jiffies, g=25953, q=216 ncpus=2) task:udevd state:R running task stack:23736 pid:8217 tgid:8217 ppid:5232 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 eb dd 23 11 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900042971d0 EFLAGS: 00000206 RAX: 7b0485c21d030d00 RBX: 0000000000000202 RCX: 7b0485c21d030d00 RDX: 0000000000000001 RSI: ffffffff8ddad7d0 RDI: ffffffff8c037100 RBP: ffff8880339f4718 R08: ffffc90004297358 R09: 0000000000000000 R10: ffffc900042973b8 R11: fffff52000852e79 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e33cda0 R15: ffff8880339f3c00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4710 [inline] slab_alloc_node mm/slub.c:5008 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5015 vm_area_dup+0x2b/0x680 mm/vma_init.c:123 __split_vma+0x1a9/0xa00 mm/vma.c:515 vms_gather_munmap_vmas+0x2e2/0x12e0 mm/vma.c:1359 do_vmi_align_munmap+0x268/0x440 mm/vma.c:1527 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584 __vm_munmap+0x207/0x380 mm/vma.c:3155 __do_sys_munmap mm/mmap.c:1080 [inline] __se_sys_munmap mm/mmap.c:1077 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b18b1e097 RSP: 002b:00007ffe3b55c978 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 000055aca1d86520 RCX: 00007f7b18b1e097 RDX: 000055aca1d8afb8 RSI: 0000000000000200 RDI: 00007f7b19151000 RBP: 0000000000000006 R08: 0000000000000030 R09: 000055aca1d8f440 R10: 0000000000000040 R11: 0000000000000246 R12: 000055aca1d96520 R13: 00007f7b1921d39c R14: 0000000000000c00 R15: 0000000000000009 rcu: rcu_preempt kthread starved for 9302 jiffies! g25953 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 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 07/12/2025 RIP: 0010:mark_usage kernel/locking/lockdep.c:4633 [inline] RIP: 0010:__lock_acquire+0x62e/0xd20 kernel/locking/lockdep.c:5191 Code: 24 11 a9 00 00 03 00 74 38 85 c9 74 1d 48 8b 3c 24 4c 89 f6 ba 01 00 00 00 e8 0e 26 00 00 48 8b 3c 24 85 c0 0f 84 77 06 00 00 <83> bf d4 0a 00 00 00 74 55 48 8b 3c 24 4c 89 f6 ba 05 00 00 00 eb RSP: 0018:ffffffff8e007a70 EFLAGS: 00000046 RAX: 00000000000e006d RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffffff8e0951c0 RBP: 000000000000006d R08: 0000000000000000 R09: ffffffff81b29cd7 R10: dffffc0000000000 R11: fffffbfff1f87d67 R12: 0000000000020000 R13: 0000000000000000 R14: ffffffff8e095cb0 R15: ffffffff8e095cb0 FS: 0000000000000000(0000) GS:ffff8881259fa000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33217ff8 CR3: 000000002f4d6000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0xcf/0x1c0 include/linux/seqlock.h:72 get_jiffies_update kernel/time/tick-sched.c:873 [inline] tick_nohz_next_event+0x47/0x3e0 kernel/time/tick-sched.c:897 tick_nohz_idle_stop_tick+0x144/0xc60 kernel/time/tick-sched.c:1218 cpuidle_idle_call kernel/sched/idle.c:188 [inline] do_idle+0x1e3/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:756 start_kernel+0x3a9/0x410 init/main.c:1109 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147