rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=153785, q=77 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295088463-4295077961), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g153785 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:25592 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 schedule+0xbf/0x180 kernel/sched/core.c:6636 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 24074 Comm: syz.6.4883 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__kasan_check_read+0x0/0x10 mm/kasan/shadow.c:31 Code: d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 70 47 be 8c eb 0a 48 c7 c7 a8 47 be 8c 4c 89 fe e8 06 6b cd 08 31 db eb d7 cc cc <89> f6 48 8b 0c 24 31 d2 e9 d3 ec ff ff 0f 1f 00 89 f6 48 8b 0c 24 RSP: 0018:ffffc90000007fc0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802c941dc0 RDX: 0000000000010000 RSI: 0000000000000008 RDI: ffffffff8ea0b468 RBP: ffff8880b8e271c0 R08: ffffffff8179c4a1 R09: fffffbfff1d4168e R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fc51990a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000040000006b000 CR3: 000000005c3f9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:444 [inline] cpu_online include/linux/cpumask.h:1030 [inline] trace_local_timer_exit arch/x86/include/asm/trace/irq_vectors.h:41 [inline] __sysvec_apic_timer_interrupt+0x1a3/0x5b0 arch/x86/kernel/apic/apic.c:1125 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: a1 84 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e dc ae f6 48 89 df e8 f6 1a b0 f6 e8 51 6d d5 f6 fb bf 01 00 00 00 d6 9b a2 f6 65 8b 05 f7 71 46 75 85 c0 74 02 5b c3 e8 94 95 44 RSP: 0018:ffffc9000476fb30 EFLAGS: 00000286 RAX: 2bca25ccb19be900 RBX: ffff88807d5fd340 RCX: ffffffff973c0103 RDX: dffffc0000000000 RSI: ffffffff8b0c1d40 RDI: 0000000000000001 RBP: ffffc9000476fc70 R08: dffffc0000000000 R09: ffffed100fabfa69 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1100fabfafb R13: 000000001c000004 R14: 0000000000000021 R15: ffff88807d5fd7d8 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x151f/0x17a0 kernel/signal.c:2874 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc518b8d167 Code: ff ff 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 RSP: 002b:00007fc51990a0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007fc518da5fa8 RCX: 00007fc518b8d169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc518da5fa8 RBP: 00007fc518da5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc518da5fac R13: 0000000000000000 R14: 00007ffd88e583a0 R15: 00007ffd88e58488