rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12273
rcu: (detected by 1, t=10502 jiffies, g=60689, q=8503 ncpus=2)
task:syz.5.2124 state:R running task stack:24600 pid:12273 tgid:12272 ppid:11198 task_flags:0x40054c flags:0x00080001
Call Trace:
sched_show_task+0x4aa/0x5f0 kernel/sched/core.c:8155
rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline]
print_other_cpu_stall+0xfca/0x1380 kernel/rcu/tree_stall.h:681
check_cpu_stall kernel/rcu/tree_stall.h:856 [inline]
rcu_pending kernel/rcu/tree.c:3679 [inline]
rcu_sched_clock_irq+0x939/0x1050 kernel/rcu/tree.c:2716
update_process_times+0x234/0x2d0 kernel/time/timer.c:2475
tick_sched_handle kernel/time/tick-sched.c:298 [inline]
tick_nohz_handler+0x42b/0x770 kernel/time/tick-sched.c:319
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x3bc/0xb10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x455/0x950 kernel/time/hrtimer.c:2215
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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 cd ce 63 f6 f7 c3 00 02 00 00 74 05 e8 30 de 8f f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 24 f4 55 f6 65 8b 05 7d 2f 5c 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc90006057828 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8d769ba8 RDI: 0000000000000001
RBP: ffffc90006057940 R08: ffffffff8faeccf7 R09: 1ffffffff1f5d99e
R10: dffffc0000000000 R11: fffffbfff1f5d99f R12: dffffc0000000000
R13: 1ffff92000c0af10 R14: ffffffff8e9f6a80 R15: ffffffff8e9f6a80
unlock_rt_mutex_safe kernel/locking/rtmutex.c:350 [inline]
rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1467
spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
vga_put drivers/pci/vgaarb.c:562 [inline]
vga_arb_release+0x27c/0x5c0 drivers/pci/vgaarb.c:1439
__fput+0x461/0xa70 fs/file_table.c:510
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x22c0 kernel/exit.c:1004
do_group_exit+0x21b/0x2d0 kernel/exit.c:1147
get_signal+0x1284/0x1330 kernel/signal.c:3038
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c3c54ce59
Code: Unable to access opcode bytes at 0x7f2c3c54ce2f.
RSP: 002b:00007f2c3a7a6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 000000000000000b RBX: 00007f2c3c7c5fa0 RCX: 00007f2c3c54ce59
RDX: 000000000000000b RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007f2c3c5e2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2c3c7c6038 R14: 00007f2c3c7c5fa0 R15: 00007fffd34b2be8
rcu: rcu_preempt kthread timer wakeup didn't happen for 10451 jiffies! g60689 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=29019
rcu: rcu_preempt kthread starved for 10452 jiffies! g60689 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27440 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5402 [inline]
__schedule+0x16f9/0x5500 kernel/sched/core.c:7204
__schedule_loop kernel/sched/core.c:7283 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7298
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11b0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 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: 12273 Comm: syz.5.2124 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 cd ce 63 f6 f7 c3 00 02 00 00 74 05 e8 30 de 8f f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 24 f4 55 f6 65 8b 05 7d 2f 5c 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc90006057828 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8d769ba8 RDI: 0000000000000001
RBP: ffffc90006057940 R08: ffffffff8faeccf7 R09: 1ffffffff1f5d99e
R10: dffffc0000000000 R11: fffffbfff1f5d99f R12: dffffc0000000000
R13: 1ffff92000c0af10 R14: ffffffff8e9f6a80 R15: ffffffff8e9f6a80
FS: 0000000000000000(0000) GS:ffff888125d7e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83bb523ed0 CR3: 00000000a84b0000 CR4: 00000000003526f0
Call Trace:
unlock_rt_mutex_safe kernel/locking/rtmutex.c:350 [inline]
rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1467
spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
vga_put drivers/pci/vgaarb.c:562 [inline]
vga_arb_release+0x27c/0x5c0 drivers/pci/vgaarb.c:1439
__fput+0x461/0xa70 fs/file_table.c:510
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x22c0 kernel/exit.c:1004
do_group_exit+0x21b/0x2d0 kernel/exit.c:1147
get_signal+0x1284/0x1330 kernel/signal.c:3038
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c3c54ce59
Code: Unable to access opcode bytes at 0x7f2c3c54ce2f.
RSP: 002b:00007f2c3a7a6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 000000000000000b RBX: 00007f2c3c7c5fa0 RCX: 00007f2c3c54ce59
RDX: 000000000000000b RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007f2c3c5e2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2c3c7c6038 R14: 00007f2c3c7c5fa0 R15: 00007fffd34b2be8
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12273 Comm: syz.5.2124 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:do_raw_spin_lock+0x0/0x2f0 kernel/locking/spinlock_debug.c:114
Code: 8e 00 eb 89 89 d9 80 e1 07 80 c1 03 38 c1 7c b7 48 89 df e8 22 8c 8e 00 eb ad 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0018:ffffc90006057860 EFLAGS: 00000082
RAX: 712cc9a677847e00 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 000000003ccf2a00 RSI: ffffffff8d9d04f2 RDI: ffffffff8e9f6a80
RBP: ffffc90006057940 R08: ffffffff8b3cb997 R09: ffffffff8e9f6a98
R10: dffffc0000000000 R11: fffffbfff1f5d99f R12: 1ffff92000c0af19
R13: dffffc0000000000 R14: ffffffff8e9f6a80 R15: ffffc900060578c0
FS: 0000000000000000(0000) GS:ffff888125d7e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb3fc157000 CR3: 000000000dfb8000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock_irqsave+0x4c/0x60 kernel/locking/spinlock.c:166
rtlock_slowlock kernel/locking/rtmutex.c:1917 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x157/0x400 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:45 [inline]
vga_put drivers/pci/vgaarb.c:556 [inline]
vga_arb_release+0x1fb/0x5c0 drivers/pci/vgaarb.c:1439
__fput+0x461/0xa70 fs/file_table.c:510
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x70f/0x22c0 kernel/exit.c:1004
do_group_exit+0x21b/0x2d0 kernel/exit.c:1147
get_signal+0x1284/0x1330 kernel/signal.c:3038
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c3c54ce59
Code: Unable to access opcode bytes at 0x7f2c3c54ce2f.
RSP: 002b:00007f2c3a7a6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 000000000000000b RBX: 00007f2c3c7c5fa0 RCX: 00007f2c3c54ce59
RDX: 000000000000000b RSI: 0000200000000100 RDI: 0000000000000009
RBP: 00007f2c3c5e2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2c3c7c6038 R14: 00007f2c3c7c5fa0 R15: 00007fffd34b2be8