rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=c4d4/1/0x4000000000000000 softirq=139583/139584 fqs=15
rcu: (detected by 1, t=10502 jiffies, g=171989, q=1370 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 24000 Comm: dhcpcd-run-hook Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
RIP: 0010:lock_is_held_type+0x4e/0x150 kernel/locking/lockdep.c:5939
Code: fe 90 07 85 c0 0f 85 d5 00 00 00 65 4c 8b 2d 81 b8 90 07 41 83 bd 8c 0b 00 00 00 0f 85 bf 00 00 00 89 f5 49 89 fe 9c 41 5c fa <48> c7 c7 11 f6 fb 8d e8 b6 19 00 00 65 ff 05 ff fd 90 07 41 83 bd
RSP: 0018:ffffc90000007da0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000010000
RDX: ffff88805b813d80 RSI: 00000000ffffffff RDI: ffff8880b8628298
RBP: 00000000ffffffff R08: ffff88807b1d1317 R09: ffff88807b1d1308
R10: dffffc0000000000 R11: ffffed100f63a263 R12: 0000000000000046
R13: ffff88805b813d80 R14: ffff8880b8628298 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125290000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c31e2ce CR3: 0000000027157000 CR4: 0000000000350ef0
Call Trace:
lock_is_held include/linux/lockdep.h:249 [inline]
__run_hrtimer kernel/time/hrtimer.c:1896 [inline]
__hrtimer_run_queues+0x20c/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline]
RIP: 0010:lock_release+0x67/0x3c0 kernel/locking/lockdep.c:5881
Code: 0f a3 05 cc c8 8e 0e 73 0d e8 45 f7 08 00 84 c0 0f 84 94 02 00 00 83 3d 86 fb 8e 0e 00 0f 84 1c 02 00 00 65 8b 05 69 66 97 11 <85> c0 0f 85 0d 02 00 00 65 4c 8b 3d b1 20 97 11 41 83 bf 8c 0b 00
RSP: 0018:ffffc900062ef4f0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff823c9eaa RCX: 0000000080000003
RDX: 0000000000000000 RSI: ffffffff8c28ac40 RDI: ffffffff8c28ac00
RBP: 0000000000000001 R08: ffffffff823c9eaa R09: ffffffff8e95ce20
R10: dffffc0000000000 R11: fffff94000222ae9 R12: dffffc0000000000
R13: ffffffff823c9eaa R14: ffffffff8e95ce20 R15: ffff88813febc100
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock_sched include/linux/rcupdate.h:960 [inline]
pfn_valid+0x3b2/0x480 include/linux/mmzone.h:2291
page_table_check_clear+0x21/0x4f0 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
clear_full_ptes include/linux/pgtable.h:905 [inline]
zap_present_folio_ptes mm/memory.c:1645 [inline]
zap_present_ptes mm/memory.c:1714 [inline]
do_zap_pte_range mm/memory.c:1816 [inline]
zap_pte_range mm/memory.c:1918 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x366d/0x4b40 mm/memory.c:2093
unmap_vmas+0x379/0x530 mm/memory.c:2162
exit_mmap+0x280/0x9e0 mm/mmap.c:1300
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x18e/0x250 kernel/exit.c:581
do_exit+0x6a2/0x22c0 kernel/exit.c:963
do_group_exit+0x21b/0x2d0 kernel/exit.c:1117
__do_sys_exit_group kernel/exit.c:1128 [inline]
__se_sys_exit_group kernel/exit.c:1126 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1126
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa0e584c6c5
Code: Unable to access opcode bytes at 0x7fa0e584c69b.
RSP: 002b:00007fff9de31a28 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fff9de31d04 RCX: 00007fa0e584c6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007fff9de31b20 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fff9de31d60 R14: 00007fa0e5a5c000 R15: 0000563ccb651d98
rcu: rcu_preempt kthread starved for 10379 jiffies! g171989 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
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+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: 1 UID: 0 PID: 24001 Comm: syz.7.5467 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfcd/0x13d0 kernel/smp.c:892
Code: c0 75 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 7a 05 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 01 0c 00 eb 37 90 43 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a
RSP: 0018:ffffc90005207560 EFLAGS: 00000246
RAX: ffffffff81b9bb36 RBX: ffff8880b873c148 RCX: 0000000000080000
RDX: ffffc90011200000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900052076a0 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: 1ffff110170c8589
R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000
FS: 00007f61113056c0(0000) GS:ffff888125390000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f605accba70 CR3: 00000000a18af000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 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+0x5c3/0x10b0 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+0x1af/0xa30 mm/mmu_gather.c:423
tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:549
unmap_region+0x2a5/0x330 mm/vma.c:491
vms_clear_ptes mm/vma.c:1303 [inline]
vms_complete_munmap_vmas+0x493/0xc60 mm/vma.c:1345
do_vmi_align_munmap+0x3b7/0x4b0 mm/vma.c:1604
do_vmi_munmap+0x252/0x2d0 mm/vma.c:1652
__vm_munmap+0x22c/0x3d0 mm/vma.c:3285
__do_sys_munmap mm/mmap.c:1079 [inline]
__se_sys_munmap mm/mmap.c:1076 [inline]
__x64_sys_munmap+0x60/0x70 mm/mmap.c:1076
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f611039cc07
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 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:00007f6111304e08 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000004000000 RCX: 00007f611039cc07
RDX: 0000000004000000 RSI: 0000000008400000 RDI: 00007f6106000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f6111304ee0 R14: 00007f6111304ea0 R15: 00007f6106000000