rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10503 jiffies, g=7089, q=156) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294958193-4294947690), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10503 jiffies! g7089 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:27792 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x84/0x290 mm/kasan/generic.c:189 Code: 49 c1 e9 03 4b 8d 1c 21 49 89 df 4d 29 df 49 83 ff 10 7f 29 4d 85 ff 0f 84 38 01 00 00 4c 89 cb 48 f7 d3 4c 01 f3 41 80 3b 00 <0f> 85 86 01 00 00 49 ff c3 48 ff c3 75 ee e9 18 01 00 00 44 89 dd RSP: 0018:ffffc900000072d0 EFLAGS: 00000046 RAX: 1ffff92000000e01 RBX: fffffffffffffff5 RCX: ffffffff8100f5ce RDX: 0000000000000001 RSI: 0000000000000060 RDI: ffffc90000007380 RBP: 0000000000000000 R08: ffffc900000073df R09: 1ffff92000000e7b R10: dffffc0000000000 R11: fffff52000000e71 R12: dffffc0000000001 R13: dffffc0000000000 R14: 1ffff92000000e70 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4639bb9640 CR3: 000000007bd54000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memset+0x1e/0x40 mm/kasan/shadow.c:44 perf_callchain_kernel+0x10e/0x720 arch/x86/events/core.c:2767 get_perf_callchain+0x356/0x460 kernel/events/callchain.c:200 perf_callchain kernel/events/core.c:7606 [inline] perf_prepare_sample+0x352/0x1cd0 kernel/events/core.c:7633 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable include/trace/events/preemptirq.h:40 [inline] trace_hardirqs_on_prepare+0x193/0x1f0 kernel/trace/trace_preemptirq.c:32 irqentry_exit+0x4b/0x70 kernel/entry/common.c:421 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 12 f2 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007c60 EFLAGS: 00000206 RAX: e4962531a80ff900 RBX: 1ffff92000000f90 RCX: e4962531a80ff900 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980 RBP: ffffc90000007d28 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: ffffffff8c322f00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] rebalance_domains+0xa0a/0xb30 kernel/sched/fair.c:10660 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:730 Code: b7 48 89 df e8 66 73 f8 f7 eb ad e8 4f af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 77 16 60 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8c007dc8 EFLAGS: 000002c6 RAX: e4962531a80ff900 RBX: ffffffff8c0bc480 RCX: e4962531a80ff900 RDX: 0000000000000001 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980 RBP: ffffffff8c007ef8 R08: ffff8880b903b30b R09: 1ffff11017207661 R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffffffff1817890 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffffffff1800fc4 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21f/0x580 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x489/0x540 init/main.c:1154 secondary_startup_64_no_verify+0xb1/0xbb INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.174 msecs