rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5309/1:b..l
	(detected by 1, t=10502 jiffies, g=13125, q=601)
task:modprobe        state:R  running task     stack:27200 pid: 5309 ppid:  5265 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:preempt_count kernel/rcu/tree.c:1163 [inline]
RIP: 0010:rcu_lockdep_current_cpu_online+0x2/0x130 kernel/rcu/tree.c:1168
Code: 07 12 8c e8 20 0a 97 02 eb 93 89 d9 80 e1 07 38 c1 7c c2 48 89 df e8 4d 82 58 00 eb b8 66 2e 0f 1f 84 00 00 00 00 00 90 41 57 <41> 56 41 54 53 65 8b 0d 2a bd 9e 7e b0 01 f7 c1 00 00 f0 00 0f 85
RSP: 0018:ffffc9000374f868 EFLAGS: 00000202
RAX: 0000000000009e01 RBX: 0000000000000000 RCX: a1261c00286edc00
RDX: 0000000000000000 RSI: ffffffff8a59e7e0 RDI: ffffffff8a59e7a0
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: dffffc0000000000
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffff8bbc2d10
 rcu_read_lock_held_common kernel/rcu/update.c:112 [inline]
 rcu_read_lock_held+0x1a/0x40 kernel/rcu/update.c:309
 __aa_task_raw_label security/apparmor/include/cred.h:76 [inline]
 aa_get_task_label+0xd3/0x2c0 security/apparmor/task.c:29
 apparmor_task_getsecid+0x25/0x120 security/apparmor/lsm.c:733
 security_task_getsecid_subj+0x5f/0xc0 security/security.c:1847
 ima_file_check+0x83/0x100 security/integrity/ima/ima_main.c:532
 do_open fs/namei.c:3618 [inline]
 path_openat+0x2735/0x2f30 fs/namei.c:3750
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777
 do_sys_openat2+0x142/0x4a0 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f40363980ba
RSP: 002b:00007ffcee7c5b88 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffcee7c5c00 RCX: 00007f40363980ba
RDX: 0000000000080000 RSI: 00007ffcee7c5c00 RDI: 00000000ffffff9c
RBP: 00007ffcee7c5bf0 R08: 00007ffcee7c5df7 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000000000000001b
R13: 00007f4036374050 R14: 00007ffcee7c5e10 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10538 jiffies! g13125 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:27880 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 5310 Comm: syz.3.25 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 be 2b b1 f7 48 89 df e8 86 00 b2 f7 e8 21 9a d2 f7 fb bf 01 00 00 00 <e8> 56 22 a6 f7 65 8b 05 e7 1f 57 76 85 c0 74 02 5b c3 e8 f4 2a 55
RSP: 0018:ffffc90003a6fbc0 EFLAGS: 00000282
RAX: 5f9984e766db3000 RBX: ffff88807910c0c0 RCX: 5f9984e766db3000
RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100f221819
R10: ffffed100f221819 R11: 1ffff1100f221818 R12: ffff88807910c0c0
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
 spin_unlock_irq include/linux/spinlock.h:414 [inline]
 get_signal+0x11d6/0x12c0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1727130be7
Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007f17263a00e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f1727357fa8 RCX: 00007f1727130be9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1727357fa8
RBP: 00007f1727357fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1727358038 R14: 00007fff367e8400 R15: 00007fff367e84e8
 </TASK>
sched: RT throttling activated