rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=dccc/1/0x4000000000000000 softirq=75127/75128 fqs=6
rcu: (detected by 1, t=10502 jiffies, g=66597, q=775 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14315 Comm: syz.2.3359 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3798 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline]
RIP: 0010:__lock_acquire+0x851/0x1a40 kernel/locking/lockdep.c:5237
Code: 05 44 bb 84 14 0f 83 b2 09 00 00 49 be eb 83 b5 80 46 86 c8 61 48 8b 4c 24 08 4c 0f af f1 49 c1 ee 2d 4a 8b 04 f5 a0 8e a7 97 <4e> 8d 2c f5 a0 8e a7 97 48 85 c0 74 1f 48 83 e8 08 48 85 c0 74 16
RSP: 0018:ffffc90000007c58 EFLAGS: 00000006
RAX: ffffffff946a5968 RBX: ffff8880285c0d08 RCX: dde87c7b4ea25df8
RDX: 00000000a0a951fc RSI: 000000000647f4ab RDI: 00000000584ee8af
RBP: ffff8880285c0000 R08: 0000000099c2e1a5 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000000 R12: dde87c7b4ea25df8
R13: 0000000000000009 R14: 000000000001af95 R15: 0000000000000009
FS: 00007f2b533996c0(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33612ff8 CR3: 000000004f64d000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166
debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:936
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:2000 [inline]
__hrtimer_run_queues+0x2e9/0x9c0 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:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 3b df 7d 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 86 c4 3c 0f 0f 82 ac 02 00 00 8b 35 4e f8 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd de 7d 12 0f 85 ec 02 00 00 48 83 c4
RSP: 0018:ffffc9000398f340 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e17cd15 RDI: ffffffff8c400c80
RBP: ffffffff8ebe6040 R08: 00000000c7614b4b R09: 000000000000001e
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:938 [inline]
pfn_valid include/linux/mmzone.h:2270 [inline]
page_table_check_set+0x6b/0x920 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_clone3+0x214/0x290 kernel/fork.c:3050
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: 0033:0x7f2b5259de59
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:00007f2b53398ef8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 0000000000000058 RCX: 00007f2b5259de59
RDX: 00007f2b53398f10 RSI: 0000000000000058 RDI: 00007f2b53398f10
RBP: 00007f2b52633e6f R08: 0000000000000000 R09: 0000000000000058
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2b52826038 R14: 00007f2b52825fa0 R15: 00007ffe2f3a46d8
rcu: rcu_preempt kthread starved for 10490 jiffies! g66597 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:27592 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: 1 UID: 0 PID: 5607 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x16c0 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 95 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31
RSP: 0018:ffffc90003807618 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fd3abd
RDX: ffff888075ae4a80 RSI: ffffffff81fd3a97 RDI: ffff888075ae4a80
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS: 0000555560893500(0000) GS:ffff888123eec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33710ff8 CR3: 000000005a862000 CR4: 00000000003526f0
DR0: 000004000002002c DR1: fffeffffff7fff02 DR2: 0000000080000002
DR3: 0000000000000003 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
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
dup_mmap+0x1307/0x21b0 mm/mmap.c:1905
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: 0033:0x7fd33c7c68d2
Code: 89 e7 e8 71 8b f7 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 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007fff38a9a770 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fff38a9a770 RCX: 00007fd33c7c68d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fff38a9a8fc R08: 0000000000000000 R09: 0000000000000001
R10: 00005555608937d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000054f5a R15: 00007fff38a9a950