rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10506 jiffies, g=235813, q=370 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4295095015-4295084509), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10506 jiffies! g235813 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x389/0x470 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3718 Comm: syz.2.8588 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__lock_acquire+0x273/0x2cf0 kernel/locking/lockdep.c:-1 Code: e8 c2 61 4d 03 4d 89 f1 48 8b 74 24 18 44 8b 74 24 20 48 83 bc 24 20 01 00 00 00 0f 85 ce fe ff ff 44 89 74 24 20 44 89 3c 24 <8b> bc 24 38 01 00 00 4c 8b 84 24 28 01 00 00 4c 8b 74 24 08 4d 8d RSP: 0018:ffffc90000007b80 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff93e11370 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff9a6802b8 RBP: 0000000000000001 R08: 0000000000000001 R09: ffffffff9a6802b8 R10: dffffc0000000000 R11: ffffed100ee94063 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 00007f073ee296c0(0000) GS:ffff88812529c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fad459456b8 CR3: 000000003765b000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 debug_object_deactivate+0x6c/0x3a0 lib/debugobjects.c:900 debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline] __run_hrtimer kernel/time/hrtimer.c:1898 [inline] __hrtimer_run_queues+0x23a/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061 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:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 9d 38 f8 f5 f7 c3 00 02 00 00 74 05 e8 d0 d2 23 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 b7 e9 f5 65 8b 05 ad 2e 8e 07 85 c0 74 18 5b 41 5e e9 7c 2f RSP: 0018:ffffc90005be7d28 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000202 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8dfa4398 RDI: 0000000000000001 RBP: ffffc90005be7e30 R08: ffffffff90302af7 R09: 1ffffffff206055e R10: dffffc0000000000 R11: fffffbfff206055f R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9a47e818 R15: ffffc90005be7e60 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] do_settimeofday64+0x336/0x570 kernel/time/timekeeping.c:1584 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline] __x64_sys_clock_settime+0x253/0x2a0 kernel/time/posix-timers.c:1108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f073df9ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f073ee29028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f073e215fa0 RCX: 00007f073df9ce59 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f073e032d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f073e216038 R14: 00007f073e215fa0 R15: 00007fff165e0bf8