rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=accc/1/0x4000000000000000 softirq=32972/32974 fqs=10
rcu: (detected by 0, t=10502 jiffies, g=37469, q=681 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8426 Comm: syz.0.1163 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_acquire+0x8a/0x350 kernel/locking/lockdep.c:5918
Code: 83 3d 49 4d d7 0e 00 0f 84 e9 00 00 00 48 8b b4 24 88 00 00 00 4c 89 e7 e8 33 7f 94 00 83 3d 2c 4d d7 0e 00 0f 84 e4 00 00 00 <65> 8b 05 57 7e f2 11 85 c0 0f 85 d5 00 00 00 65 48 8b 2d 97 39 f2
RSP: 0018:ffffc90000a18c58 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000001000004
RDX: 0000000000000000 RSI: ffffffff8be95d80 RDI: 1ffffffff358b7ea
RBP: ffffffff9ac5bf30 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90000a18d20 R11: fffff520001431a6 R12: ffffffff9ac5bf50
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124dc8000(0000) knlGS:0000000000000000
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000056d3c20c CR3: 000000000eb48000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:155 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:181
debug_object_activate+0xb7/0x420 lib/debugobjects.c:873
debug_hrtimer_activate kernel/time/hrtimer.c:486 [inline]
debug_activate kernel/time/hrtimer.c:529 [inline]
enqueue_hrtimer+0xa9/0x2c0 kernel/time/hrtimer.c:1136
__run_hrtimer kernel/time/hrtimer.c:2090 [inline]
__hrtimer_run_queues+0x4ce/0xa10 kernel/time/hrtimer.c:2131
hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2250
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pfn_valid+0x1c/0x490 arch/x86/include/asm/cpufeature.h:-1
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 49 89 fe e8 ee 01 84 ff e9 01 04 00 00 e8 e4 01 84 ff <49> bc 00 00 00 00 00 fc ff df e9 26 04 00 00 e8 d0 01 84 ff 48 c7
RSP: 0018:ffffc9000e44f2d8 EFLAGS: 00000293
RAX: ffffffff8243ed68 RBX: 0000000000000001 RCX: ffff888074ecbe80
RDX: 0000000000000000 RSI: 0000000000064c57 RDI: 0000000400000000
RBP: ffffc9000e44f650 R08: ffffea00019315c7 R09: 1ffffd40003262b8
R10: dffffc0000000000 R11: fffff940003262b9 R12: 1ffff110058e3252
R13: 00000000f6600000 R14: 0000000000064c57 R15: 00000000f6452000
page_table_check_clear+0x21/0x500 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:879 [inline]
zap_present_folio_ptes mm/memory.c:1779 [inline]
zap_present_ptes mm/memory.c:1861 [inline]
do_zap_pte_range mm/memory.c:1963 [inline]
zap_pte_range mm/memory.c:2065 [inline]
zap_pmd_range mm/memory.c:2151 [inline]
zap_pud_range mm/memory.c:2179 [inline]
zap_p4d_range mm/memory.c:2200 [inline]
__zap_vma_range+0x3a12/0x4f80 mm/memory.c:2240
unmap_vmas+0x390/0x550 mm/memory.c:2309
exit_mmap+0x293/0x9f0 mm/mmap.c:1315
__mmput+0x118/0x420 kernel/fork.c:1193
exit_mm+0x18e/0x240 kernel/exit.c:592
do_exit+0x6cd/0x2360 kernel/exit.c:974
do_group_exit+0x22d/0x2f0 kernel/exit.c:1129
get_signal+0x121b/0x12c0 kernel/signal.c:3112
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
__do_fast_syscall_32+0x437/0x6a0 arch/x86/entry/syscall_32.c:294
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:316
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f360ec
Code: Unable to access opcode bytes at 0xf7f360c2.
RSP: 002b:00000000f53f650c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: 000000000000004c RBX: 0000000000000004 RCX: 00000000800012c0
RDX: 0000000000008010 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10481 jiffies! g37469 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:28104 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 0 UID: 0 PID: 5628 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:csd_lock_wait kernel/smp.c:363 [inline]
RIP: 0010:csd_lock kernel/smp.c:396 [inline]
RIP: 0010:smp_call_function_many_cond+0x61e/0x1500 kernel/smp.c:944
Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 31 56 0c 00 41 83 e7 01 75 07 e8 26 51 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01
RSP: 0000:ffffc900041873e0 EFLAGS: 00000293
RAX: ffffffff81bb9a2e RBX: ffff8880b87414c8 RCX: ffff88807f193e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004187530 R08: ffff88807f19541f R09: 1ffff1100fe32a83
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff110170e8299
R13: 0000000000000001 R14: ffff8880b87414c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124cc8000(0063) knlGS:00000000574be480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000056d3c20c CR3: 0000000068dd0000 CR4: 00000000003526f0
Call Trace:
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x8ff/0x1090 arch/x86/mm/tlb.c:1435
dup_mmap+0x1758/0x1dc0 mm/mmap.c:1884
dup_mm kernel/fork.c:1543 [inline]
copy_mm+0x115/0x480 kernel/fork.c:1595
copy_process+0x1e79/0x4400 kernel/fork.c:2311
kernel_clone+0x2d7/0x940 kernel/fork.c:2771
__do_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:255 [inline]
__se_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:241 [inline]
__ia32_compat_sys_ia32_clone+0x1b4/0x230 arch/x86/kernel/sys_ia32.c:241
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
__do_fast_syscall_32+0x27a/0x6a0 arch/x86/entry/syscall_32.c:291
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:316
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fb30ec
Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8
RSP: 002b:00000000f759fc80 EFLAGS: 00000206 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000574be4e8
RBP: 00000000f759fcb4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000