rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=32157, q=266 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294983806-4294973304), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g32157 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:27552 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10021 Comm: syz.2.1085 Not tainted 6.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0xc9d/0x3c40 kernel/locking/lockdep.c:5223 Code: 48 c7 c2 30 8c 62 90 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 c7 c0 30 8c 62 90 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 b0 28 00 00 8b 1d 95 1e cc 0e 85 db 75 40 44 8b 5c 24 RSP: 0018:ffffc90000a18af0 EFLAGS: 00000006 RAX: 0000000000000003 RBX: d57e1d102ea6ccdd RCX: ffffffff81967022 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000057e1d10d RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2dd8598 R10: ffffffff96ec2cc7 R11: 0000000000000001 R12: ffffed1004ebd5e5 R13: ffff8880275ea440 R14: 0000000000000002 R15: ffff8880275eaf58 FS: 00007f899f0856c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000040000001b000 CR3: 0000000053018000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_deactivate+0x13b/0x370 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:460 [inline] debug_deactivate kernel/time/hrtimer.c:502 [inline] __run_hrtimer kernel/time/hrtimer.c:1769 [inline] __hrtimer_run_queues+0x47c/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x220/0xcc0 kernel/sched/core.c:5252 Code: a9 0a 00 00 44 8b 0d 33 e4 d9 0e 45 85 c9 0f 85 c0 01 00 00 48 89 df e8 ae f8 ff ff e8 99 f1 38 00 fb 65 48 8b 1d 20 31 7b 7e <48> 8d bb 08 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc9000caf7710 EFLAGS: 00000206 RAX: 000000000000207b RBX: ffff8880275ea440 RCX: 1ffffffff20c42b1 RDX: 0000000000000000 RSI: ffffffff8b6ced60 RDI: ffffffff8bd359e0 RBP: ffffc9000caf7758 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90625917 R11: 0000000000000000 R12: ffff8880b873fa30 R13: ffff8880313d2440 R14: ffff888070e26400 R15: ffff8880b863ec00 context_switch kernel/sched/core.c:5381 [inline] __schedule+0xf4b/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 rdmsr_safe_on_cpu+0x1de/0x210 arch/x86/lib/msr-smp.c:181 msr_read+0x19e/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x1df/0xbf0 fs/read_write.c:563 ksys_read+0x12b/0x250 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f899e18d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 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 RSP: 002b:00007f899f085038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f899e3a5fa0 RCX: 00007f899e18d169 RDX: 0000000000018ff8 RSI: 0000400000019680 RDI: 0000000000000003 RBP: 00007f899e20e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f899e3a5fa0 R15: 00007fff43813508