rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=8b8c/1/0x4000000000000000 softirq=47999/48000 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=75941, q=345 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2751 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x22/0x70 kernel/locking/spinlock.c:194 Code: 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 55 48 89 f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 76 ef e3 f6 48 89 df e8 6e 67 e4 f6 c5 00 02 00 00 75 1f 9c 58 f6 c4 02 75 2f bf 01 00 00 00 e8 c5 RSP: 0018:ffffc900001f0e28 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff8880b992bf40 RCX: ffffffff8168a493 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8880b992bf40 RBP: 0000000000000046 R08: 0000000000000000 R09: ffffed10173257e8 R10: ffff8880b992bf43 R11: 0000000000000004 R12: ffff8880b992bf40 R13: 17ac2b1e08000000 R14: ffff88802244e340 R15: ffffffff88a3e5f0 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f30474d56c6 CR3: 000000000cd79000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1684 [inline] __hrtimer_run_queues+0x58b/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:arch_check_zapped_pte+0x44/0x140 arch/x86/mm/pgtable.c:909 Code: 89 e3 48 c7 04 24 b3 8a b5 41 48 c7 44 24 08 53 d3 95 8c 48 c1 eb 03 48 c7 44 24 10 20 51 3b 81 48 8d 04 2b c7 00 f1 f1 f1 f1 40 04 00 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 44 24 58 31 RSP: 0018:ffffc9000581f650 EFLAGS: 00000216 RAX: fffff52000b03eca RBX: 1ffff92000b03eca RCX: ffffc9000581f580 RDX: ffff888086f1bb80 RSI: 80000000402bd007 RDI: ffff888084f05500 RBP: dffffc0000000000 R08: 0000000000000000 R09: fffffbfff1e32d6a R10: ffffffff8f196b57 R11: 0000000000000003 R12: ffff888084f05500 R13: ffff888080883388 R14: dffffc0000000000 R15: 0000000000000007 zap_pte_range mm/memory.c:1442 [inline] zap_pmd_range mm/memory.c:1583 [inline] zap_pud_range mm/memory.c:1612 [inline] zap_p4d_range mm/memory.c:1633 [inline] unmap_page_range+0x106e/0x2b70 mm/memory.c:1654 unmap_single_vma+0x194/0x2b0 mm/memory.c:1700 unmap_vmas+0x229/0x470 mm/memory.c:1744 exit_mmap+0x1ad/0xa70 mm/mmap.c:3311 __mmput+0x12a/0x4d0 kernel/fork.c:1349 mmput+0x62/0x70 kernel/fork.c:1371 exit_mm kernel/exit.c:567 [inline] do_exit+0x9a5/0x2ad0 kernel/exit.c:856 do_group_exit+0xd4/0x2a0 kernel/exit.c:1018 get_signal+0x23b5/0x2790 kernel/signal.c:2904 arch_do_signal_or_restart+0x90/0x7f0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:105 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline] syscall_exit_to_user_mode+0x156/0x2b0 kernel/entry/common.c:212 do_syscall_64+0xe0/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f2e5f27cd29 Code: Unable to access opcode bytes at 0x7f2e5f27ccff. RSP: 002b:00007f2e5ffd8178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f2e5f3abf88 RCX: 00007f2e5f27cd29 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2e5f3abf88 RBP: 00007f2e5f3abf80 R08: 00007f2e5ffd86c0 R09: 00007f2e5ffd86c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2e5f3abf8c R13: 000000000000000b R14: 00007ffef6589910 R15: 00007ffef65899f8 rcu: rcu_preempt kthread starved for 10500 jiffies! g75941 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:27904 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5399 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6726 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6816 schedule_timeout+0x137/0x290 kernel/time/timer.c:2183 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 14325 Comm: kworker/u4:19 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x4e9/0x1550 kernel/smp.c:855 Code: 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ae c6 0b 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 24 0e 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc90015387930 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9942060 RCX: ffffffff817c0118 RDX: ffff888029860000 RSI: ffffffff817c00f2 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed101732840d R13: 0000000000000001 R14: ffff8880b9942068 R15: ffff8880b983dec0 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3046900ee2 CR3: 000000000cd79000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2016 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2226 text_poke_flush arch/x86/kernel/alternative.c:2417 [inline] text_poke_flush arch/x86/kernel/alternative.c:2414 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2424 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:830 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242