rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=fbc4/1/0x4000000000000000 softirq=23056/23056 fqs=7
rcu: (detected by 0, t=10502 jiffies, g=24141, q=486 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7026 Comm: syz.4.285 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:151 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x2b/0x80 kernel/locking/spinlock.c:198
Code: 0f 1e fa 55 48 89 f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 56 a0 28 f6 48 89 df e8 de ef 28 f6 f7 c5 00 02 00 00 75 23 9c <58> f6 c4 02 75 37 bf 01 00 00 00 e8 a5 ff 17 f6 65 8b 05 ee b8 a6
RSP: 0018:ffffc90000a08d50 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff9b98ea28 RCX: ffffffff81e5c753
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9b98ea28
RBP: 0000000000000002 R08: 0000000000000000 R09: fffffbfff3731d45
R10: ffffffff9b98ea2b R11: 0000000000000000 R12: 0000000000000002
R13: ffff888034126300 R14: dffffc0000000000 R15: 1ffff920001411b2
FS: 00007f97c87116c0(0000) GS:ffff888123ee7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000002f956000 CR4: 00000000003526f0
Call Trace:
debug_object_activate+0x343/0x4b0 lib/debugobjects.c:891
debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline]
debug_activate kernel/time/hrtimer.c:528 [inline]
enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109
__run_hrtimer kernel/time/hrtimer.c:2048 [inline]
__hrtimer_run_queues+0x6ed/0x9c0 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213
Code: 64 00 be 03 00 00 00 5b e9 12 90 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 85 b3 59 12 <48> 8b 34 24 65 48 8b 15 61 b3 59 12 a9 00 01 ff 00 74 1b f6 c4 01
RSP: 0018:ffffc900058d7448 EFLAGS: 00000282
RAX: 0000000080000002 RBX: 000000000005a657 RCX: ffffffff82868808
RDX: 0000000080000002 RSI: 0000000000000000 RDI: ffff8880278aa540
RBP: 0000000080000002 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000002 R11: 0000000000000000 R12: 0000000000000008
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
page_table_check_set+0x1a5/0x930 mm/page_table_check.c:105
__page_table_check_ptes_set+0x27a/0x4e0 mm/page_table_check.c:212
page_table_check_ptes_set include/linux/page_table_check.h:83 [inline]
set_ptes include/linux/pgtable.h:447 [inline]
__copy_present_ptes mm/memory.c:1118 [inline]
copy_present_ptes mm/memory.c:1197 [inline]
copy_pte_range mm/memory.c:1320 [inline]
copy_pmd_range mm/memory.c:1408 [inline]
copy_pud_range mm/memory.c:1445 [inline]
copy_p4d_range mm/memory.c:1469 [inline]
copy_page_range+0x2197/0x5b20 mm/memory.c:1555
dup_mmap+0xd44/0x21b0 mm/mmap.c:1840
dup_mm kernel/fork.c:1543 [inline]
copy_mm kernel/fork.c:1595 [inline]
copy_process+0x4588/0x8030 kernel/fork.c:2289
kernel_clone+0x176/0x9d0 kernel/fork.c:2748
__do_sys_clone+0xd9/0x120 kernel/fork.c:2889
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f97c779de99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f97c8710fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f97c7a26090 RCX: 00007f97c779de99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f97c7833eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f97c7a26128 R14: 00007f97c7a26090 R15: 00007fff714b78b8
rcu: rcu_preempt kthread starved for 10488 jiffies! g24141 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:26200 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 7020 Comm: syz.2.283 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 0b 69 b8 f5 cc
RSP: 0018:ffffc900070df2f0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fd46fd
RDX: ffff888033c42540 RSI: ffffffff81fd46d7 RDI: ffff888033c42540
RBP: ffff8880b8541240 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a8249 R14: 0000000000000001 R15: ffff8880b843c880
FS: 0000000000000000(0000) GS:ffff888123de7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 0000000058e24000 CR4: 00000000003526f0
Call Trace:
native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0x587/0x16c0 kernel/smp.c:892
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
__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+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline]
zap_pte_range mm/memory.c:1961 [inline]
zap_pmd_range mm/memory.c:2020 [inline]
zap_pud_range mm/memory.c:2048 [inline]
zap_p4d_range mm/memory.c:2069 [inline]
__zap_vma_range+0x23c8/0x4a30 mm/memory.c:2109
unmap_vmas+0x299/0x5f0 mm/memory.c:2178
exit_mmap+0x1ef/0xa00 mm/mmap.c:1300
__mmput+0x12a/0x410 kernel/fork.c:1187
mmput+0x67/0x80 kernel/fork.c:1210
exit_mm kernel/exit.c:615 [inline]
do_exit+0x8b1/0x2ae0 kernel/exit.c:997
do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
get_signal+0x1ec7/0x21e0 kernel/signal.c:3046
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x6f0 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:318 [inline]
do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd4bab9de99
Code: Unable to access opcode bytes at 0x7fd4bab9de6f.
RSP: 002b:00007fd4bbafb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffe0 RBX: 00007fd4bae26180 RCX: 00007fd4bab9de99
RDX: 00000000000000a0 RSI: 0000200000000340 RDI: 0000000000000005
RBP: 00007fd4bac33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd4bae26218 R14: 00007fd4bae26180 R15: 00007ffca4192fc8