rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12047/1:b..l P12062/1:b..l P6704/1:b..l rcu: (detected by 1, t=10503 jiffies, g=44109, q=857 ncpus=2) task:kworker/0:11 state:R running task stack:21464 pid:6704 tgid:6704 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x45/0x2f0 kernel/locking/lockdep.c:5879 Code: 79 bf 3d 12 48 89 44 24 10 31 c0 0f 1f 44 00 00 65 8b 05 92 bf 3d 12 83 f8 07 0f 87 38 02 00 00 89 c0 48 0f a3 05 db 10 13 0f <0f> 82 b1 01 00 00 8b 3d a3 42 13 0f 85 ff 0f 84 25 01 00 00 65 8b RSP: 0018:ffffc9001cfefb10 EFLAGS: 00000297 RAX: 0000000000000000 RBX: ffffffff8e5c1120 RCX: ffffffff89b91088 RDX: ffff88805294a440 RSI: ffffffff89b909e9 RDI: ffffffff8e5c1120 RBP: ffffffff9b2c82ec R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff89b909e9 R13: 00000000000705d1 R14: dffffc0000000000 R15: 0000000000002417 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] gc_worker+0x99e/0x16e0 net/netfilter/nf_conntrack_core.c:1617 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:syz-executor state:R running task stack:25512 pid:12062 tgid:12062 ppid:5830 task_flags:0x400000 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:debug_lockdep_rcu_enabled+0x28/0x40 kernel/rcu/update.c:320 Code: 90 90 f3 0f 1e fa 8b 05 96 69 18 05 85 c0 74 20 8b 05 70 9a 18 05 85 c0 74 16 65 48 8b 05 18 17 43 08 8b 80 ec 0a 00 00 85 c0 <0f> 94 c0 0f b6 c0 e9 cd 02 03 00 66 2e 0f 1f 84 00 00 00 00 00 0f RSP: 0018:ffffc9000404f518 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000404fe68 RCX: ffffc90004050001 RDX: ffffc9000404fe70 RSI: ffffc9000404fe38 RDI: ffffc9000404f5a0 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000011153 R12: ffffc9000404f5e0 R13: ffffc9000404f590 R14: ffffc9000404fe68 R15: ffffc9000404f5c4 rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3de/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __set_page_owner+0x91/0x550 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507 vm_area_alloc_pages mm/vmalloc.c:3642 [inline] __vmalloc_area_node mm/vmalloc.c:3720 [inline] __vmalloc_node_range_noprof+0x72f/0x14b0 mm/vmalloc.c:3893 vmalloc_user_noprof+0x9e/0xe0 mm/vmalloc.c:4046 kcov_ioctl+0x4c/0x730 kernel/kcov.c:716 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe23258e76b RSP: 002b:00007ffe7bdb49a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007fe23258e76b RDX: 0000000000080000 RSI: ffffffff80086301 RDI: 00000000000000da RBP: 00007fe2327b61f8 R08: 00000000000000d9 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:syz-executor state:R running task stack:25512 pid:12047 tgid:12047 ppid:5830 task_flags:0x400000 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288 irqentry_exit+0x36/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x20 kernel/kcov.c:314 Code: bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 2a fe ff ff 66 2e 0f 1f 84 00 00 00 RSP: 0018:ffffc9000380f7d0 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: ffffffff822da0b6 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffed1003ba6eed R10: ffff88801dd3776f R11: 0000000000000000 R12: ffff88801dd37720 R13: ffff88801dd3776c R14: 0000000000000000 R15: dffffc0000000000 __page_table_check_zero+0x2a6/0x5d0 mm/page_table_check.c:143 page_table_check_alloc include/linux/page_table_check.h:35 [inline] post_alloc_hook+0x1af/0x230 mm/page_alloc.c:1852 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507 vm_area_alloc_pages mm/vmalloc.c:3642 [inline] __vmalloc_area_node mm/vmalloc.c:3720 [inline] __vmalloc_node_range_noprof+0x72f/0x14b0 mm/vmalloc.c:3893 vmalloc_user_noprof+0x9e/0xe0 mm/vmalloc.c:4046 kcov_ioctl+0x4c/0x730 kernel/kcov.c:716 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7c1f98e76b RSP: 002b:00007ffe840af3a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007f7c1f98e76b RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7 RBP: 00007f7c1fbb5f40 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 9635 jiffies! g44109 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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: 12008 Comm: syz.1.1461 Not tainted 6.16.0-syzkaller-11105-ga6923c06a3b2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: e9 0d 40 5b 00 be 03 00 00 00 5b e9 82 f1 26 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 88 f7 19 12 65 8b 05 99 f7 19 12 a9 00 01 ff 00 74 1d RSP: 0018:ffffc90000007cd8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff888079e30000 RCX: ffffffff817e75e2 RDX: ffff888079e30000 RSI: ffffffff817e72e3 RDI: 0000000000000005 RBP: ffff888079e30000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff888079e30920 R13: 0000000000000020 R14: 0000000000000021 R15: ffff888026b9f2c0 FS: 00007f18683f66c0(0000) GS:ffff8881246c8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa6d752e856 CR3: 000000004edd5000 CR4: 00000000003526f0 Call Trace: complete_signal+0x3d3/0xc50 kernel/signal.c:1003 posixtimer_send_sigqueue+0x415/0x1060 kernel/signal.c:2080 posix_timer_queue_signal+0x106/0x170 kernel/time/posix-timers.c:365 posix_timer_fn+0x3a/0x80 kernel/time/posix-timers.c:380 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 fa a1 02 f6 48 89 df e8 e2 f5 02 f6 e8 dd 47 2e f6 fb bf 01 00 00 00 f2 f2 f2 f5 65 8b 05 9b 61 40 08 85 c0 74 06 5b e9 41 4d 00 00 RSP: 0018:ffffc9000409fcd8 EFLAGS: 00000206 RAX: 0000000008f43b63 RBX: ffff888035a6ca00 RCX: ffffffff81c3655f RDX: 0000000000000000 RSI: ffffffff8de4c8a5 RDI: 0000000000000001 RBP: ffff888035a6ce00 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90aad197 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000021 R14: 0000000000000400 R15: ffff888035a6ca00 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1e6c/0x26d0 kernel/signal.c:3037 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f186758eb67 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:00007f18683f6038 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f18677b5fa0 RCX: 00007f186758eb69 RDX: 00000000ffffffff RSI: 0000000000000006 RDI: 000020000000cffc RBP: 00007f1867611df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f18677b5fa0 R15: 00007ffdba75ad38