rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=eea4/1/0x4000000000000000 softirq=21329/21337 fqs=5
rcu: (detected by 0, t=10502 jiffies, g=15897, q=754 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6480 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lock_release+0x89/0x3e0 kernel/locking/lockdep.c:5881
Code: a8 df 0d 00 0f 84 44 02 00 00 65 8b 05 e0 fc d0 10 85 c0 0f 85 35 02 00 00 65 4c 8b 3c 25 08 20 6e 92 41 83 bf 2c 0b 00 00 00 <0f> 85 1e 02 00 00 49 81 3e 40 d3 31 93 0f 84 11 02 00 00 48 c7 44
RSP: 0018:ffffc90000a08c38 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000806 RCX: 0f4a8bc265336200
RDX: 0000000000010000 RSI: ffffffff8bbf05c0 RDI: ffffffff8bbf0580
RBP: ffffc90000a08d30 R08: ffffffff8f7cdb77 R09: 1ffffffff1ef9b6e
R10: dffffc0000000000 R11: fffffbfff1ef9b6f R12: dffffc0000000000
R13: ffffffff81ada638 R14: ffff8880b8927ad8 R15: ffff88802774bc80
FS: 0000000000000000(0000) GS:ffff88812623e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f159cb34e9c CR3: 000000000dd38000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194
__run_hrtimer kernel/time/hrtimer.c:1773 [inline]
__hrtimer_run_queues+0x408/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 bb cc d0 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900030773d8 EFLAGS: 00000206
RAX: 0f4a8bc265336200 RBX: 0000000000000000 RCX: 0f4a8bc265336200
RDX: 0000000000000000 RSI: ffffffff8d8f3ee2 RDI: ffffffff8bbf05e0
RBP: ffffffff81738d25 R08: 0000000000000000 R09: ffffffff81738d25
R10: ffffc90003077598 R11: ffffffff81ac2d30 R12: 0000000000000002
R13: ffffffff8df3d2e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4970 [inline]
slab_alloc_node mm/slub.c:5280 [inline]
kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5287
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x100/0x570 lib/debugobjects.c:403
debug_objects_fill_pool lib/debugobjects.c:725 [inline]
debug_object_activate+0x383/0x420 lib/debugobjects.c:814
debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline]
__call_rcu_common kernel/rcu/tree.c:3108 [inline]
call_rcu+0xaa/0x9c0 kernel/rcu/tree.c:3243
slab_free_hook mm/slub.c:2503 [inline]
slab_free mm/slub.c:6630 [inline]
kmem_cache_free+0x4b5/0x690 mm/slub.c:6740
task_work_run+0x1d4/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:966
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
__do_sys_exit_group kernel/exit.c:1118 [inline]
__se_sys_exit_group kernel/exit.c:1116 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f159cc936c5
Code: Unable to access opcode bytes at 0x7f159cc9369b.
RSP: 002b:00007ffe4cff2388 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f159cd94fe8 RCX: 00007f159cc936c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007ffe4cff2318 R09: 0000000000000000
R10: 00007ffe4cff21b0 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f159cd93680 R15: 00007f159cd95000
rcu: rcu_preempt kthread starved for 10492 jiffies! g15897 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:27288 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 6479 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 6f 0b 00 eb e4 44
RSP: 0018:ffffc90003817540 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff11017127ffd RCX: ffff88802ad89e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900038176c0 R08: ffffffff8f7cdb77 R09: 1ffffffff1ef9b6e
R10: dffffc0000000000 R11: fffffbfff1ef9b6f R12: ffff8880b893ffe8
R13: dffffc0000000000 R14: ffff8880b883b240 R15: 0000000000000001
FS: 00007f5b3bc53c80(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc76f3aff8 CR3: 00000000792ca000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline]
flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1471
dup_mmap+0x1594/0x1b10 mm/mmap.c:1873
dup_mm kernel/fork.c:1489 [inline]
copy_mm+0x13c/0x4b0 kernel/fork.c:1541
copy_process+0x1706/0x3c00 kernel/fork.c:2181
kernel_clone+0x21e/0x840 kernel/fork.c:2609
__do_sys_clone kernel/fork.c:2750 [inline]
__se_sys_clone kernel/fork.c:2734 [inline]
__x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b3bded636
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:00007ffc76f3af90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffc76f3af98 RCX: 00007f5b3bded636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000558035555c30 R08: 0000000000000000 R09: 0000000000000000
R10: 00007f5b3bc53f50 R11: 0000000000000246 R12: 0000558035563ce8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000