rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=72097, q=482 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295005636-4294995134), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g72097 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:29168 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7322 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 18072 Comm: syz.3.3869 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:rcu_read_lock include/linux/rcupdate.h:841 [inline] RIP: 0010:advance_sched+0x729/0xd20 net/sched/sch_taprio.c:992 Code: 00 48 8d 05 00 00 00 00 50 31 d2 31 f6 48 c7 c7 c0 9c 7e 8e e8 58 29 48 f8 e8 e3 a2 ee 01 31 ff 89 c3 89 c6 e8 58 80 6c f8 58 <85> db 0f 85 8c 02 00 00 e8 9a 85 6c f8 48 8b 7c 24 28 e8 40 b6 c3 RSP: 0018:ffffc90000007de8 EFLAGS: 00000046 RAX: ffffffff899d0f17 RBX: 0000000000000000 RCX: ffffffff899d0f38 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88804cfb2540 RBP: ffff888056ca1800 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffffc90000007ff8 R12: 0000000000000000 R13: 18b9924e075f8b52 R14: ffff888034e21c00 R15: ffff888034e21c00 FS: 00007f00cb6876c0(0000) GS:ffff888124375000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f00ca84f156 CR3: 00000000492c0000 CR4: 00000000003526f0 DR0: 000000007fffffff DR1: 00000000000001f8 DR2: 0000000000000004 DR3: 0000000000000008 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/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+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 06 97 56 f6 48 89 df e8 8e e6 56 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 f4 45 f6 65 8b 05 1e 09 7c 08 85 c0 74 16 5b RSP: 0018:ffffc900053bfb28 EFLAGS: 00000246 RAX: 0000000000000046 RBX: ffffffff9b1a5358 RCX: ffffffff8211d68f RDX: 0000000000000000 RSI: ffffffff8c1c9c00 RDI: ffffffff8b8ea722 RBP: 0000000000000286 R08: 0000000000000000 R09: fffffbfff21af8b2 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9b1a50c0 R13: 0000000000000005 R14: ffffc900053bfc80 R15: 7fffffffffffffff class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] __do_adjtimex+0x892/0xe70 kernel/time/timekeeping.c:2952 do_adjtimex+0xa0/0x370 kernel/time/timekeeping.c:2995 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime+0x177/0x290 kernel/time/posix-timers.c:1181 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f00ca79ce59 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:00007f00cb687028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f00caa15fa0 RCX: 00007f00ca79ce59 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007f00ca832d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f00caa16038 R14: 00007f00caa15fa0 R15: 00007fffe080bcf8