rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5202/1:b..l rcu: (detected by 1, t=10503 jiffies, g=15501, q=479 ncpus=2) task:udevd state:R running task stack:24824 pid:5202 tgid:5202 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5253 [inline] __schedule+0x17b2/0x4d40 kernel/sched/core.c:6861 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7188 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__kasan_check_byte+0x12/0x40 mm/kasan/common.c:579 Code: cf fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 41 56 53 48 89 f3 49 89 fe e8 0e 15 00 00 <84> c0 75 16 be 01 00 00 00 4c 89 f7 31 d2 48 89 d9 89 c3 e8 a6 03 RSP: 0018:ffffc900035f7768 EFLAGS: 00000293 RAX: 0000000000000001 RBX: ffffffff81ab7419 RCX: 211d1c94bd354700 RDX: 0000000000000000 RSI: ffffffff81ab7419 RDI: 1ffffffff1be8298 RBP: ffffffff81ab73fd R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff81acfc00 R12: 0000000000000002 R13: ffffffff8df414c0 R14: ffffffff8df414c0 R15: 0000000000000000 kasan_check_byte include/linux/kasan.h:401 [inline] lock_acquire+0x84/0x340 kernel/locking/lockdep.c:5842 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] is_module_text_address+0x39/0x1e0 kernel/module/main.c:3845 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 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:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5295 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2499 [inline] getname_maybe_null include/linux/fs.h:2506 [inline] vfs_fstatat+0x43/0x170 fs/stat.c:370 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 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: 0033:0x7f60c5f11b0a RSP: 002b:00007ffcd035dd48 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffcd035e1e0 RCX: 00007f60c5f11b0a RDX: 00007ffcd035dd50 RSI: 00007ffcd035e1e0 RDI: 00000000ffffff9c RBP: 000055fe85211910 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcd035dde0 R13: 0000000000000100 R14: 000055fe4898fbe0 R15: 00007ffcd035e860 rcu: rcu_preempt kthread starved for 10487 jiffies! g15501 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:27080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5253 [inline] __schedule+0x17b2/0x4d40 kernel/sched/core.c:6861 __schedule_loop kernel/sched/core.c:6943 [inline] schedule+0x165/0x360 kernel/sched/core.c:6958 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+0x52d/0xa60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: 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+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: ce 11 ca 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 63 14 22 00 f3 0f 1e fa fb f4 a3 11 ca f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: d1a4cebf15a62800 RBX: ffffffff819729e7 RCX: d1a4cebf15a62800 RDX: 0000000000000001 RSI: ffffffff8d762d2a RDI: ffffffff8bbfa900 RBP: ffffc90000197f10 R08: ffff8880b893341b R09: 1ffff11017126683 R10: dffffc0000000000 R11: ffffed1017126684 R12: ffffffff8f801370 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110038d9b70 FS: 0000000000000000(0000) GS:ffff8881261c5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3131bff8 CR3: 0000000077fab000 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:190 [inline] do_idle+0x1e7/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147