rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=6404/1/0x4000000000000000 softirq=85316/85316 fqs=0 rcu: (detected by 0, t=10506 jiffies, g=80217, q=160 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17565 Comm: syz.5.3129 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:hlock_id kernel/locking/lockdep.c:433 [inline] RIP: 0010:__lock_acquire+0x57e/0x1c90 kernel/locking/lockdep.c:5225 Code: 05 00 00 48 89 c8 89 4c 24 28 48 c1 e8 20 89 c6 89 44 24 18 01 c1 c1 c6 04 89 74 24 20 41 0f b7 45 20 66 25 ff 1f 66 89 04 24 <41> 0f b6 45 22 83 e0 03 48 83 7c 24 08 00 88 44 24 10 74 70 65 4c RSP: 0018:ffffc90000a08c40 EFLAGS: 00000006 RAX: 00000000000010e1 RBX: 0000000000000001 RCX: 00000000fffffffe RDX: 0000000000000000 RSI: ffff8880281f2fd8 RDI: ffff8880281f2480 RBP: ffff8880281f2480 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000028 R11: 0000000000000001 R12: ffff8880281f2fb0 R13: ffff8880281f2fd8 R14: 0000000000000001 R15: 0000000000000003 FS: 00007f9eecdf96c0(0000) GS:ffff888124b0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003000 CR3: 0000000067657000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:929 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 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+0x10b/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+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 f9 35 f6 48 89 df e8 fe 4c 36 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 45 56 26 f6 65 8b 05 7e 65 3e 08 85 c0 74 16 5b RSP: 0018:ffffc9000bb57c98 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8880b8427c80 RCX: 0000000000000007 RDX: 0000000000000000 RSI: ffffffff8da2a184 RDI: ffffffff8bf06cc0 RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9081f4d7 R11: 0000000000000001 R12: 0000000000000000 R13: 1bc16c8b1120d9a4 R14: dffffc0000000000 R15: ffff8880b8427c80 clock_was_set+0x599/0x870 kernel/time/hrtimer.c:965 do_settimeofday64+0x364/0x550 kernel/time/timekeeping.c:1460 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1131 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1115 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1115 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9eebf8efc9 Code: 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 01 48 RSP: 002b:00007f9eecdf9038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f9eec1e5fa0 RCX: 00007f9eebf8efc9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f9eec011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9eec1e6038 R14: 00007f9eec1e5fa0 R15: 00007fff99902398 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g80217 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=70827 rcu: rcu_preempt kthread starved for 10506 jiffies! g80217 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:28120 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+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245