rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6455/1:b..l
rcu: (detected by 1, t=10619 jiffies, g=16869, q=1749 ncpus=2)
task:udevd state:R running task stack:25696 pid:6455 tgid:6455 ppid:5193 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7095
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:389 [inline]
wp_page_copy mm/memory.c:3881 [inline]
do_wp_page+0x42bf/0x5a00 mm/memory.c:4241
handle_pte_fault mm/memory.c:6333 [inline]
__handle_mm_fault mm/memory.c:6455 [inline]
handle_mm_fault+0x1520/0x3310 mm/memory.c:6624
do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f1d8b2b5b69
RSP: 002b:00007ffc11673c20 EFLAGS: 00010202
RAX: 00007f1d8b3f21d0 RBX: 0000563e964a5540 RCX: 0000563e964a5540
RDX: 0000563e964a5540 RSI: 00007f1d8b3f21d0 RDI: 0000563e964a5540
RBP: 00007f1d8b3f1ac0 R08: 0000000000002760 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000049c0
R13: 0000563e964a9f00 R14: 000000000001a000 R15: 00007f1d8b3f1ac0
rcu: rcu_preempt kthread timer wakeup didn't happen for 6007 jiffies! g16869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=7356
rcu: rcu_preempt kthread starved for 6008 jiffies! g16869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5193 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4703 [inline]
RIP: 0010:__lock_acquire+0x735/0x2cf0 kernel/locking/lockdep.c:5221
Code: 0b 00 00 4d 85 ff 0f 84 8e 00 00 00 41 83 ff 31 0f 83 ca 23 00 00 4b 8d 04 bf 4d 89 ec 41 8b 6d 20 48 8b 4c 24 20 8b 44 c1 f8 <31> e8 25 00 60 00 00 0f 95 c1 89 0c 24 31 c9 f7 d8 48 19 c9 48 09
RSP: 0018:ffffc90000007b10 EFLAGS: 00000087
RAX: 00000000000c4073 RBX: 37609dba68070e38 RCX: ffff88807c83e6d8
RDX: 0000000000000008 RSI: ffff88807c83e728 RDI: ffff88807c83db80
RBP: 00000000000c4000 R08: ffffffff84b9a57c R09: ffffffff9a4c9170
R10: ffff8880258f3308 R11: ffffed1004b1e663 R12: ffff88807c83e728
R13: ffff88807c83e728 R14: ffff88807c83db80 R15: 0000000000000002
FS: 00007f1d8b9c8880(0000) GS:ffff888125454000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc11672c50 CR3: 000000007ee42000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
debug_object_deactivate+0x6c/0x3a0 lib/debugobjects.c:890
debug_hrtimer_deactivate kernel/time/hrtimer.c:451 [inline]
__run_hrtimer kernel/time/hrtimer.c:1753 [inline]
__hrtimer_run_queues+0x2c5/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1911
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x460 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:find_vmap_lowest_match mm/vmalloc.c:1586 [inline]
RIP: 0010:__alloc_vmap_area mm/vmalloc.c:1857 [inline]
RIP: 0010:alloc_vmap_area+0x44b/0x14b0 mm/vmalloc.c:2079
Code: ff 0f 84 33 04 00 00 4d 8d 67 10 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 45 02 12 00 <4d> 8b 2c 24 49 f7 c5 ef ff ff ff 4c 89 6c 24 60 75 0a e8 ae af a7
RSP: 0018:ffffc900042f75c0 EFLAGS: 00010246
RAX: 1ffff11004ec421e RBX: 0000000000010fff RCX: dffffc0000000000
RDX: ffffffffffff8000 RSI: 0000000000000004 RDI: ffffc900042f7540
RBP: ffffc900042f76f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200085eea8 R12: ffff8880276210f0
R13: 0000000000009000 R14: ffffc90000000000 R15: ffff8880276210e0
__get_vm_area_node+0x1f8/0x300 mm/vmalloc.c:3232
__vmalloc_node_range_noprof+0x372/0x1730 mm/vmalloc.c:4024
__vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
alloc_thread_stack_node kernel/fork.c:355 [inline]
dup_task_struct+0x275/0x9a0 kernel/fork.c:924
copy_process+0x508/0x3cd0 kernel/fork.c:2050
kernel_clone+0x248/0x8e0 kernel/fork.c:2653
__do_sys_clone kernel/fork.c:2794 [inline]
__se_sys_clone kernel/fork.c:2778 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1d8b2f1636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc11673bc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc11673bc8 RCX: 00007f1d8b2f1636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000563e9647a910 R08: 0000000000000000 R09: 0000000000000210
R10: 00007f1d8b9c8b50 R11: 0000000000000246 R12: 00007ffc11673f80
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000