rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=69349, q=143) rcu: All QSes seen, last rcu_preempt kthread activity 10496 (4295051354-4295040858), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10496 jiffies! g69349 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26488 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 15349 Comm: syz.0.2321 Not tainted 5.15.179-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3932 [inline] rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619 update_process_times+0x196/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x13/0x80 kernel/kcov.c:273 Code: 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 49 ff c1 4c 89 09 c3 0f 1f 00 4c 8b 04 24 65 48 8b 0d 14 d1 81 7e 65 8b 05 15 d1 81 7e <25> 00 01 ff 00 74 10 3d 00 01 00 00 75 57 83 b9 34 16 00 00 00 74 RSP: 0018:ffffc90002e8fa98 EFLAGS: 00000293 RAX: 0000000080000000 RBX: 0000000000000344 RCX: ffff8880555d3b80 RDX: 0000000000000000 RSI: 0000000000000344 RDI: 00007ffd9f7762c4 RBP: ffffc90002e8fc50 R08: ffffffff812f4c5c R09: fffff520005d1fb0 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 00007ffd9f775f80 R14: 0000000000000344 R15: 00007ffd9f7762c4 __chk_range_not_ok arch/x86/include/asm/uaccess.h:33 [inline] fpu__restore_sig+0x16c/0x1100 arch/x86/kernel/fpu/signal.c:456 restore_sigcontext+0x638/0x710 arch/x86/kernel/signal.c:139 __do_sys_rt_sigreturn+0x190/0x250 arch/x86/kernel/signal.c:674 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ffab44db17e Code: 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> 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 RSP: 002b:00007ffd9f776368 EFLAGS: 00000213 RAX: 0000000000000004 RBX: 00000000000fd4a0 RCX: ffffffffffffffa8 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffab46f3fac RBP: 0000000000000032 R08: 0000000000000010 R09: 0000000d9f77665f R10: 00007ffd9f776460 R11: 0000000000000246 R12: 00007ffab46f3fac R13: 00007ffd9f776460 R14: 00000000000fd4d2 R15: 00007ffd9f776480