rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=23729, q=503 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4294976196-4294965695), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g23729 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:27080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 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 08/18/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 24 08 1f 0c 48 89 de 5b e9 33 6c 59 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 30 c4 92 65 8b 15 28 52 04 11 81 e2 00 01 ff 00 RSP: 0018:ffffc90000007c98 EFLAGS: 00000202 RAX: ffffffff81add10e RBX: ffff8880b8627d88 RCX: c956a82a3ff02400 RDX: ffffffff8e0951c0 RSI: ffffffff8c03aac0 RDI: ffffffff8c03aa80 RBP: ffffc90000007df0 R08: ffffffff8fc45d37 R09: 1ffffffff1f88ba6 R10: dffffc0000000000 R11: fffffbfff1f88ba7 R12: ffff888028441418 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8627d40 FS: 0000000000000000(0000) GS:ffff8881259dd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa1275d6098 CR3: 0000000030eba000 CR4: 00000000003526f0 Call Trace: trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline] __run_hrtimer kernel/time/hrtimer.c:1780 [inline] __hrtimer_run_queues+0x5ce/0xc60 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5228 Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 ff 84 f5 09 e8 9a 56 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 58 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffffff8e007af8 EFLAGS: 00000282 RAX: c956a82a3ff02400 RBX: 0000000000000000 RCX: c956a82a3ff02400 RDX: 0000000000000000 RSI: ffffffff8dbc41e9 RDI: ffffffff8c03aae0 RBP: ffffffff8e007b50 R08: ffffffff8fc45d37 R09: 1ffffffff1f88ba6 R10: dffffc0000000000 R11: fffffbfff1f88ba7 R12: ffffffff8e0951c0 R13: dffffc0000000000 R14: ffff888029f08000 R15: ffff8880b863abd8 context_switch kernel/sched/core.c:5363 [inline] __schedule+0x17a0/0x4cc0 kernel/sched/core.c:6964 schedule_idle+0x52/0x90 kernel/sched/core.c:7087 do_idle+0x4a7/0x510 kernel/sched/idle.c:358 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147