rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10585/1:b..l rcu: (detected by 1, t=10502 jiffies, g=36133, q=396 ncpus=2) task:syz-executor state:R running task stack:20624 pid:10585 tgid:10585 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6869 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6893 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1691 [inline] zap_pmd_range mm/memory.c:1739 [inline] zap_pud_range mm/memory.c:1768 [inline] zap_p4d_range mm/memory.c:1789 [inline] unmap_page_range+0x36b1/0x40e0 mm/memory.c:1810 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1900 exit_mmap+0x275/0xc40 mm/mmap.c:1874 __mmput+0x115/0x390 kernel/fork.c:1347 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x28e0 kernel/exit.c:926 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd880174257 RSP: 002b:00007ffd0c8fac70 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 00000000000000a1 RCX: 00007fd880174257 RDX: 0000000040000000 RSI: 00007ffd0c8faccc RDI: 00000000ffffffff RBP: 00007ffd0c8faccc R08: 0000000000000000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 00005555661375eb R13: 0000555566137590 R14: 00000000000595f6 R15: 00007ffd0c8fad20 rcu: rcu_preempt kthread starved for 10497 jiffies! g36133 f0x0 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:24912 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:32 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:147 [inline] RIP: 0010:lock_acquire+0x237/0x550 kernel/locking/lockdep.c:5828 Code: 0f 85 a3 01 00 00 49 89 de 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 f7 e8 f7 55 8e 00 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 <42> 80 3c 2b 00 74 08 4c 89 f7 e8 ea 54 8e 00 f6 44 24 61 02 0f 85 RSP: 0018:ffffc90000007b00 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff92000000f6c RCX: 91637018a777e500 RDX: dffffc0000000000 RSI: ffffffff8c0adc20 RDI: ffffffff8c6101e0 RBP: ffffc90000007c48 R08: ffffffff942c980f R09: 1ffffffff2859301 R10: dffffc0000000000 R11: fffffbfff2859302 R12: 1ffff92000000f68 R13: dffffc0000000000 R14: ffffc90000007b60 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31613ff8 CR3: 000000000e734000 CR4: 0000000000350ef0 Call Trace: seqcount_lockdep_reader_access+0xfc/0x220 include/linux/seqlock.h:72 timekeeping_debug_get_ns kernel/time/timekeeping.c:256 [inline] timekeeping_get_ns+0x5c/0x420 kernel/time/timekeeping.c:401 ktime_get_update_offsets_now+0x90/0x250 kernel/time/timekeeping.c:2449 hrtimer_update_base kernel/time/hrtimer.c:634 [inline] hrtimer_run_softirq+0xa2/0x2c0 kernel/time/hrtimer.c:1771 handle_softirqs+0x2c7/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:schedule_debug kernel/sched/core.c:5887 [inline] RIP: 0010:__schedule+0x16f/0x4bd0 kernel/sched/core.c:6564 Code: f6 48 8b 1b 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 58 74 30 f6 48 81 3b 9d 6e ac 57 <0f> 85 ee 1e 00 00 83 7c 24 50 00 7f 5e 48 8b 44 24 28 48 8d 58 18 RSP: 0018:ffffc900001578a0 EFLAGS: 00000246 RAX: 1ffff9200002a000 RBX: ffffc90000150000 RCX: dffffc0000000000 RDX: 0000000000000010 RSI: ffffffff8c6101c0 RDI: ffffffff8c610180 RBP: ffffc90000157ab0 R08: ffffc90000157a3f R09: ffffc90000157a30 R10: dffffc0000000000 R11: fffff5200002af48 R12: 1ffff9200002af58 R13: 1ffff9200002af5c R14: ffff8880b8600000 R15: dffffc0000000000 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7012 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x13b/0x190 Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90000157c38 EFLAGS: 00000206 RAX: 91637018a777e500 RBX: 0000000000000000 RCX: ffff88801cad5a00 RDX: 0000000000000000 RSI: ffffffff8c0adc20 RDI: ffffffff8c6101e0 RBP: ffffc90000157d90 R08: ffffffff901cfeaf R09: 1ffffffff2039fd5 R10: dffffc0000000000 R11: fffffbfff2039fd6 R12: 0000000000000246 R13: ffff88801cad5a00 R14: 00000000ffffffff R15: ffffffff8e937da0 lock_is_held include/linux/lockdep.h:249 [inline] __might_resched+0xf4/0x780 kernel/sched/core.c:8615 run_ksoftirqd+0xe3/0x130 kernel/softirq.c:929 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244