rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=eaa4/1/0x4000000000000000 softirq=19798/19799 fqs=112 rcu: (detected by 0, t=10502 jiffies, g=27501, q=991 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8249 Comm: syz-executor Not tainted 6.11.0-rc3-syzkaller-00338-gc3f2d783a459 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:hlock_class kernel/locking/lockdep.c:227 [inline] RIP: 0010:__lock_acquire+0xf44/0x2040 kernel/locking/lockdep.c:5138 Code: 00 8b 1b 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 40 18 73 93 be 08 00 00 00 e8 84 eb 8a 00 48 0f a3 1d 8c 34 03 12 <0f> 83 69 02 00 00 48 69 c3 c8 00 00 00 48 8d 98 40 77 41 93 48 bf RSP: 0018:ffffc90000a18a70 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000021 RCX: ffffffff816fe3ac RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff93731840 RBP: 3ab6d40026a7fe15 R08: ffffffff93731847 R09: 1ffffffff26e6308 R10: dffffc0000000000 R11: fffffbfff26e6309 R12: 0000000000000001 R13: ffff8880223c46d8 R14: 1ffff110044788e5 R15: ffff8880223c4728 FS: 000055557e8ac500(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000200 CR3: 000000005a6ae000 CR4: 0000000000350ef0 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1693 [inline] __hrtimer_run_queues+0x670/0xd50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__page_table_check_zero+0x105/0x350 mm/page_table_check.c:153 Code: 49 c7 c5 40 69 f9 94 49 c1 ed 03 eb 0a 4c 03 25 c1 62 f3 12 49 ff c7 83 7c 24 04 3f 0f 87 e6 00 00 00 e8 5e 84 8d ff 4c 89 fd <44> 89 f1 48 d3 ed 31 ff 48 89 ee e8 2b 89 8d ff 48 85 ed 0f 85 e3 RSP: 0018:ffffc900049f7800 EFLAGS: 00000293 RAX: ffffffff82060692 RBX: dffffc0000000000 RCX: ffff8880223c3c00 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88801919bbcc RBP: 0000000000000001 R08: ffff88801919bbcf R09: 1ffff11003233779 R10: dffffc0000000000 R11: ffffed100323377a R12: ffff88801919bbd0 R13: 1ffffffff29f2d28 R14: 0000000000000000 R15: 0000000000000001 page_table_check_alloc include/linux/page_table_check.h:33 [inline] post_alloc_hook+0x206/0x230 mm/page_alloc.c:1494 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263 vm_area_alloc_pages mm/vmalloc.c:3584 [inline] __vmalloc_area_node mm/vmalloc.c:3653 [inline] __vmalloc_node_range_noprof+0xa40/0x1400 mm/vmalloc.c:3834 vmalloc_user_noprof+0x74/0x80 mm/vmalloc.c:3988 kcov_ioctl+0x59/0x640 kernel/kcov.c:715 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9775579a7b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fff261fdfe0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007f9775579a7b RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7 RBP: 00007f9775715f40 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10278 jiffies! g27501 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:25560 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 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: CPU: 0 UID: 0 PID: 5228 Comm: kworker/0:4 Not tainted 6.11.0-rc3-syzkaller-00338-gc3f2d783a459 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events once_deferred RIP: 0010:csd_lock_wait kernel/smp.c:312 [inline] RIP: 0010:smp_call_function_many_cond+0x1865/0x29d0 kernel/smp.c:856 Code: 89 e6 83 e6 01 31 ff e8 39 15 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 e4 10 0c 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 c8 10 0c 00 eb e4 44 RSP: 0018:ffffc9000311f7c0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110172688f1 RCX: ffff88802fbc5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000311f9a0 R08: ffffffff818779f7 R09: 1ffffffff26e6308 R10: dffffc0000000000 R11: fffffbfff26e6309 R12: dffffc0000000000 R13: ffff8880b9344788 R14: ffff8880b923fb40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3321eff8 CR3: 000000000e734000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xd2/0x1c0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 once_deferred+0x70/0xb0 lib/once.c:20 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 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