rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10174/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=35941, q=406 ncpus=2)
task:syz.3.1079 state:R running task stack:29256 pid:10174 tgid:10156 ppid:5849 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
irqentry_exit+0x36/0x90 kernel/entry/common.c:211
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline]
RIP: 0010:unwind_next_frame+0x1f6/0x20a0 arch/x86/kernel/unwind_orc.c:494
Code: 89 c3 39 d0 0f 83 fb 15 00 00 48 ba 00 00 00 00 00 fc ff df 89 c1 48 8d 3c 8d b4 1d ad 91 49 89 f8 49 c1 e8 03 45 0f b6 04 10 <48> 89 fa 83 e2 07 83 c2 03 44 38 c2 7c 2f 45 84 c0 74 2a 48 89 4c
RSP: 0018:ffffc9000c847708 EFLAGS: 00000a06
RAX: 0000000000012351 RBX: 0000000000000001 RCX: 0000000000012351
RDX: dffffc0000000000 RSI: 00000000000a5181 RDI: ffffffff91b1aaf8
RBP: ffffc9000c8477c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000012351 R12: ffffc9000c8477c8
R13: ffffc9000c847778 R14: ffffc9000c8477ad R15: ffffffff82235142
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:262 [inline]
__do_kmalloc_node mm/slub.c:5603 [inline]
__kmalloc_noprof+0x32f/0x880 mm/slub.c:5615
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45
tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_number_perm+0x245/0x580 security/tomoyo/file.c:723
security_file_ioctl+0x9b/0x240 security/security.c:2982
__do_sys_ioctl fs/ioctl.c:591 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0xb7/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f701bf8eacb
RSP: 002b:00007f701ce8f050 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f701c1e6218 RCX: 00007f701bf8eacb
RDX: 0000000000000000 RSI: 0000000000006364 RDI: 00000000000000da
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffffb36c877
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f701c1e6218 R14: 00007ffffb36c790 R15: 00007ffffb36c878
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g35941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=22962
rcu: rcu_preempt kthread starved for 10502 jiffies! g35941 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28096 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:562 [inline]
RIP: 0010:queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline]
RIP: 0010:do_raw_spin_unlock+0x148/0x230 kernel/locking/spinlock_debug.c:142
Code: c1 ea 03 0f b6 14 02 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 95 00 00 00 48 c7 c0 90 54 02 8e c7 43 08 ff ff ff ff <48> ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 ba 00
RSP: 0018:ffffc900000075e8 EFLAGS: 00000046
RAX: ffffffff8e025490 RBX: ffffffff9aa6a838 RCX: ffffffff81978f13
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9aa6a838
RBP: ffffffff9aa6a840 R08: 0000000000000000 R09: fffffbfff354d507
R10: ffffffff9aa6a83b R11: 0000000000000000 R12: ffffffff9aa6a848
R13: dffffc0000000000 R14: ffff8880732f0340 R15: 1ffff92000000ec6
FS: 0000000000000000(0000) GS:ffff888124e77000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001c5030 CR3: 0000000070fd4000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock_irqrestore+0x22/0x80 kernel/locking/spinlock.c:194
debug_object_deactivate+0x1ec/0x3a0 lib/debugobjects.c:888
debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline]
debug_deactivate kernel/time/hrtimer.c:483 [inline]
__run_hrtimer kernel/time/hrtimer.c:1745 [inline]
__hrtimer_run_queues+0x46f/0xad0 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x183/0x2f0 kernel/locking/lockdep.c:5893
Code: 0f c1 05 98 95 e3 11 83 f8 01 0f 85 1d 01 00 00 9c 58 f6 c4 02 0f 85 08 01 00 00 41 f7 c5 00 02 00 00 74 01 fb 48 8b 44 24 10 <65> 48 2b 05 ad 53 e3 11 0f 85 58 01 00 00 48 83 c4 18 5b 41 5c 41
RSP: 0018:ffffc90000007988 EFLAGS: 00000206
RAX: 78adf0b283533300 RBX: ffffffff8e1c23a0 RCX: ffffc90000007994
RDX: 0000000000000001 RSI: ffffffff8d800971 RDI: ffffffff8bd045c0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 00000000000090ae R12: ffffffff816a7994
R13: 0000000000000202 R14: ffffffff8de97a00 R15: 0000000000000002
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1169 [inline]
unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2514 [inline]
slab_free_after_rcu_debug+0x110/0x340 mm/slub.c:6624
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0x799/0x1530 kernel/rcu/tree.c:2861
handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 3e 5f 02 e9 d3 09 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 5f 1c 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8de07e08 EFLAGS: 000002c6
RAX: 00000000018be1fb RBX: 0000000000000000 RCX: ffffffff8b4daa89
RDX: 0000000000000000 RSI: ffffffff8d826483 RDI: ffffffff8bd045c0
RBP: fffffbfff1bd2f40 R08: 0000000000000001 R09: ffffed10170c6655
R10: ffff8880b86332ab R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8de97a00 R14: ffffffff905f9790 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x38d/0x500 kernel/sched/idle.c:330
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3f3/0x4e0 init/main.c:1111
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148