rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=51ec/1/0x4000000000000000 softirq=27730/27730 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=25901, q=306 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12706 Comm: syz.4.1570 Not tainted 6.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x10/0x18 Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <75> 06 5a c3 cc cc cc cc 56 0f b6 f0 e8 9f ff ff ff 5e 5a c3 cc cc RSP: 0018:ffffc90000a28ad0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffffffff350c72a RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9a863948 RBP: dffffc0000000000 R08: ffffffff9a86394b R09: 1ffffffff350c729 R10: dffffc0000000000 R11: fffffbfff350c72a R12: 1ffffffff350c72b R13: ffffffff9a863958 R14: ffffffff9a863950 R15: ffffffff9a863948 FS: 00007f6c5f1c96c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000400000003c80 CR3: 0000000033ade000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:582 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline] do_raw_spin_unlock+0x13c/0x8b0 kernel/locking/spinlock_debug.c:142 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock_irqrestore+0x81/0x140 kernel/locking/spinlock.c:194 debug_object_activate+0x3f7/0x580 lib/debugobjects.c:836 debug_hrtimer_activate kernel/time/hrtimer.c:455 [inline] debug_activate kernel/time/hrtimer.c:496 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1100 __run_hrtimer kernel/time/hrtimer.c:1818 [inline] __hrtimer_run_queues+0x6cb/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 fe da 22 f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 43 cc 8b f5 65 8b 05 74 1e 00 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc9000b4dfba0 EFLAGS: 00000206 RAX: 6f8809cf06f2b000 RBX: 1ffff9200169bf78 RCX: ffffffff819d4bba RDX: dffffc0000000000 RSI: ffffffff8c2ab380 RDI: 0000000000000001 RBP: ffffc9000b4dfc30 R08: ffffffff94517847 R09: 1ffffffff28a2f08 R10: dffffc0000000000 R11: fffffbfff28a2f09 R12: dffffc0000000000 R13: 1ffff9200169bf74 R14: ffffc9000b4dfbc0 R15: 0000000000000246 clock_was_set+0x686/0x810 kernel/time/hrtimer.c:984 do_settimeofday64+0x343/0x5e0 kernel/time/timekeeping.c:1381 __do_sys_clock_settime kernel/time/posix-timers.c:1135 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1119 [inline] __x64_sys_clock_settime+0x23a/0x280 kernel/time/posix-timers.c:1119 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6c5e38d169 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:00007f6c5f1c9038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f6c5e5a5fa0 RCX: 00007f6c5e38d169 RDX: 0000000000000000 RSI: 0000400000003c80 RDI: 0000000000000000 RBP: 00007f6c5e40e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6c5e5a5fa0 R15: 00007ffec42147f8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g25901 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=11748 rcu: rcu_preempt kthread starved for 10502 jiffies! g25901 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:26104 pid:18 tgid:18 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244