rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=3c5/0/0x1 softirq=10124/10124 fqs=0 (detected by 0, t=10506 jiffies, g=12189, q=293) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__lock_acquire+0x48a/0x7c60 kernel/locking/lockdep.c:4951 Code: 55 62 00 00 31 c0 4c 89 a4 24 98 00 00 00 41 83 3c 24 00 0f 95 c0 09 c3 c1 e3 0d 8b 84 24 b0 00 00 00 c1 e0 0f 0f b7 c0 09 d8 <8b> 8c 24 90 00 00 00 83 e1 03 c1 e1 10 09 c1 8b 44 24 68 83 e0 01 RSP: 0018:ffffc90000dd08c0 EFLAGS: 00000006 RAX: 0000000000004000 RBX: 0000000000004000 RCX: 1ffff11027fc7162 RDX: 00000000000009f5 RSI: 0000000000000000 RDI: ffff88813fe38b00 RBP: ffffc90000dd0b10 R08: dffffc0000000000 R09: 0000000000000001 R10: fffffbfff1ad32b6 R11: 1ffffffff1ad32b5 R12: ffff88813fe38ad4 R13: 0000000000000000 R14: 00000000000009f5 R15: ffff88813fe38af0 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000600 CR3: 000000005b4f9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] advance_sched+0x47/0x940 net/sched/sch_taprio.c:716 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730 Code: bf 48 89 df e8 26 b4 09 f8 eb b5 e8 df af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 67 43 53 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:ffffc90000d67d48 EFLAGS: 000002c2 RAX: 103403f78cb8bd00 RBX: ffff88813fe38000 RCX: 103403f78cb8bd00 RDX: 0000000000000001 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a4c0 RBP: ffffc90000d67e80 R08: dffffc0000000000 R09: ffffed1017227662 R10: ffffed1017227662 R11: 1ffff11017227661 R12: ffffffff8d6995a8 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11027fc7000 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x31f/0x430 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g12189 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=6801 rcu: rcu_preempt kthread starved for 10506 jiffies! g12189 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27848 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline] RIP: 0010:kasan_check_range+0xf/0x290 mm/kasan/generic.c:189 Code: 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 a4 01 00 00 41 57 41 56 <53> 49 89 f8 49 01 f0 0f 82 57 02 00 00 49 89 f8 49 c1 e8 2f 41 81 RSP: 0018:ffffc90000dd0ce0 EFLAGS: 00000002 RAX: ffffffff8167e901 RBX: 0000000000000000 RCX: ffffffff8167e94c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d6995a8 RBP: ffffc90000dd0e98 R08: dffffc0000000000 R09: ffff88807c0c1b40 R10: ffffed100f81836b R11: 1ffff1100f818368 R12: ffff8880b912a350 R13: 1ffff1101722546a R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000600 CR3: 000000005b4f9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_hrtimer_cancel include/trace/events/timer.h:294 [inline] debug_deactivate+0x5c/0x1c0 kernel/time/hrtimer.c:472 __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x2db/0xc40 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730 Code: bf 48 89 df e8 26 b4 09 f8 eb b5 e8 df af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 67 43 53 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:ffffc90000d67d48 EFLAGS: 000002c2 RAX: 103403f78cb8bd00 RBX: ffff88813fe38000 RCX: 103403f78cb8bd00 RDX: 0000000000000001 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a4c0 RBP: ffffc90000d67e80 R08: dffffc0000000000 R09: ffffed1017227662 R10: ffffed1017227662 R11: 1ffff11017227661 R12: ffffffff8d6995a8 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11027fc7000 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x31f/0x430 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb