rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=118265, q=236 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4295050669-4295040169), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g118265 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 rcu: Possible timer handling issue on cpu=0 timer-softirq=60474 rcu: rcu_preempt kthread starved for 10500 jiffies! g118265 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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 stack:26072 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 16 e7 5e 00 48 89 df 5b e9 5d 62 64 00 be 03 00 00 00 5b e9 12 90 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 85 b3 59 12 48 8b 34 24 65 48 8b 15 61 b3 59 RSP: 0018:ffffc90000007de0 EFLAGS: 00000002 RAX: ffffffff89c760a7 RBX: 0000000000000001 RCX: ffffffff89c760c8 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff8e891480 RBP: ffff8880330b8c00 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 18c37004ef6064c7 R14: ffff8880330b9800 R15: ffff8880330b9800 FS: 0000000000000000(0000) GS:ffff888123de7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4971dffd58 CR3: 0000000075840000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:841 [inline] advance_sched+0x9c2/0xd20 net/sched/sch_taprio.c:992 __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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 06 8d 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 b9 11 00 fb f4 bc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e807e10 EFLAGS: 00000242 RAX: 0000000004fb5db9 RBX: ffffffff8e891480 RCX: ffffffff8bb9e2d5 RDX: 0000000000000000 RSI: ffffffff8e1a474f RDI: ffffffff8c401280 RBP: fffffbfff1d12290 R08: 0000000000000001 R09: ffffed101708678d R10: ffff8880b8433c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffffffff1d00fc6 R15: dffffc0000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 rest_init+0x251/0x260 init/main.c:717 start_kernel+0x48e/0x490 init/main.c:1175 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x158