rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=42329, q=14 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294972971-4294962469), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g42329 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:26712 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 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: 8913 Comm: syz.4.1277 Not tainted 6.1.119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3737 [inline] RIP: 0010:validate_chain+0x112/0x5950 kernel/locking/lockdep.c:3793 Code: 3d 00 00 04 00 0f 85 98 04 00 00 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 60 c2 24 91 be 08 00 00 00 e8 1e c8 76 00 <48> 0f a3 1d d6 63 b9 0f 72 25 48 c7 c0 60 31 35 97 48 c1 e8 03 42 RSP: 0018:ffffc90000007720 EFLAGS: 00000056 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816b5e82 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff9124c260 RBP: ffffc900000079d0 R08: dffffc0000000000 R09: fffffbfff224984d R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffff888026968b78 R14: cf82e703b144b952 R15: 1ffff11004d2d16f FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020003c80 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 debug_object_activate+0x68/0x4e0 lib/debugobjects.c:698 debug_hrtimer_activate kernel/time/hrtimer.c:421 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x30/0x410 kernel/time/hrtimer.c:1085 __run_hrtimer kernel/time/hrtimer.c:1706 [inline] __hrtimer_run_queues+0x728/0xe50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124 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:lock_release+0x637/0xa20 kernel/locking/lockdep.c:5686 Code: 3c 3b 00 74 08 4c 89 f7 e8 86 57 77 00 f6 84 24 91 00 00 00 02 75 6f 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc900054a7180 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000a94e42 RCX: ffffc900054a7203 RDX: 0000000000000002 RSI: ffffffff8b0c1340 RDI: ffffffff8b5e6200 RBP: ffffc900054a72b0 R08: dffffc0000000000 R09: fffffbfff1d35ef6 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000a94e3c R13: 0000000000000246 R14: ffffc900054a7210 R15: dffffc0000000000 page_remove_rmap+0x819/0xed0 mm/rmap.c:1462 zap_pte_range mm/memory.c:1453 [inline] zap_pmd_range mm/memory.c:1574 [inline] zap_pud_range mm/memory.c:1603 [inline] zap_p4d_range mm/memory.c:1624 [inline] unmap_page_range+0x1217/0x2740 mm/memory.c:1645 unmap_vmas+0x48b/0x640 mm/memory.c:1730 exit_mmap+0x249/0x980 mm/mmap.c:3234 __mmput+0x115/0x3c0 kernel/fork.c:1200 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f6/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16f7/0x17d0 kernel/signal.c:2871 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: 0033:0x7f5cb8d7e919 Code: Unable to access opcode bytes at 0x7f5cb8d7e8ef. RSP: 002b:00007f5cb9c020e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f5cb8f35fa8 RCX: 00007f5cb8d7e919 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f5cb8f35fac RBP: 00007f5cb8f35fa0 R08: 0000000000000010 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f5cb8f35fac R13: 0000000000000000 R14: 00007fff247b3ef0 R15: 00007fff247b3fd8