rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 ticks this GP) idle=96bc/1/0x4000000000000000 softirq=15791/15791 fqs=162
rcu: (detected by 1, t=10502 jiffies, g=14117, q=843 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5277 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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:210 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:221
Code: 48 89 f3 49 89 fe 48 83 c7 18 48 8b 74 24 10 e8 95 38 b6 f5 4c 89 f7 e8 4d b0 b6 f5 f7 c3 00 02 00 00 74 05 e8 40 ff e2 f5 9c <58> a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00
RSP: 0018:ffffc90000007da0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000046 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b8428280
RBP: ffff88802e266300 R08: ffff8880b8428283 R09: 1ffff11017085050
R10: dffffc0000000000 R11: ffffed1017085051 R12: ffff8880b8428280
R13: ffffffff89ef9160 R14: ffff8880b8428280 R15: 1ffff1101708507a
FS: 00007f85979ba780(0000) GS:ffff888123abd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e3d36d44f0 CR3: 000000007b64e000 CR4: 00000000003526f0
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:2070 [inline]
__hrtimer_run_queues+0x2bf/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:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline]
RIP: 0010:lock_acquire+0x99/0x350 kernel/locking/lockdep.c:5918
Code: b4 24 88 00 00 00 4c 89 e7 e8 13 5f 95 00 83 3d 3c f0 d6 0f 00 0f 84 e4 00 00 00 65 8b 05 67 fd f2 12 85 c0 0f 85 d5 00 00 00 <65> 48 8b 2d a7 b8 f2 12 83 bd a4 0b 00 00 00 0f 85 c0 00 00 00 48
RSP: 0018:ffffc9000346f468 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 8000000000000001
RDX: 0000000000000000 RSI: ffffffff817821fc RDI: 1ffffffff1fab91c
RBP: 1ffff9200068debc R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000346f5f8 R11: ffffffff81b2d5e0 R12: ffffffff8fd5c8e0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5414 [inline]
__kmalloc_noprof+0x36b/0x720 mm/slub.c:5439
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
lsm_blob_alloc security/security.c:218 [inline]
lsm_task_alloc security/security.c:270 [inline]
security_task_alloc+0x4d/0x330 security/security.c:2785
copy_process+0x1c49/0x4400 kernel/fork.c:2293
kernel_clone+0x2d7/0x940 kernel/fork.c:2771
__do_sys_clone kernel/fork.c:2913 [inline]
__se_sys_clone kernel/fork.c:2897 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2897
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8597a8e636
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:00007ffd2354a5f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffd2354a5f8 RCX: 00007f8597a8e636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffd2356ab40 R08: 0000000000000000 R09: 0000000000000001
R10: 00007f85979baa50 R11: 0000000000000246 R12: 00007ffd2354a730
R13: 0000000000000000 R14: 0000000000000000 R15: 000055e3d2702ac0
rcu: rcu_preempt kthread starved for 6990 jiffies! g14117 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27688 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: 1 UID: 0 PID: 5853 Comm: dhcpcd 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+0x62d/0x1500 kernel/smp.c:944
Code: 89 fe 83 e6 01 31 ff e8 91 59 0c 00 41 83 e7 01 75 07 e8 86 54 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 00 00 00 74 1d e8 62 54 0c 00 eb dc 89 d9 80
RSP: 0018:ffffc900038bf560 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b8443728 RCX: ffff8880307b1f40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900038bf6b0 R08: ffff8880307b34df R09: 1ffff110060f669b
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff110170886e5
R13: 0000000000000000 R14: ffff8880b8443720 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888123bbd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e3d2720660 CR3: 000000007d4a8000 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+0x910/0x10b0 arch/x86/mm/tlb.c:1435
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+0xf4/0x220 mm/mmu_gather.c:549
free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline]
exit_mmap+0x1bf/0x9f0 mm/mmap.c:1300
__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
__do_sys_exit_group kernel/exit.c:1140 [inline]
__se_sys_exit_group kernel/exit.c:1138 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1138
x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8597a8e6c5
Code: Unable to access opcode bytes at 0x7f8597a8e69b.
RSP: 002b:00007ffd2356aaf8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f8597a8e6c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 00007ffd2356b108 R08: 000055e3d36ae2c0 R09: 0000000000000002
R10: 00000000000000e0 R11: 0000000000000206 R12: 00007ffd2356ab40
R13: 000055e3d36af8a0 R14: 00007ffd2356ad80 R15: 00007ffd2356ab30