rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=f294/1/0x4000000000000000 softirq=77949/77949 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=80673, q=156 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 15193 Comm: syz.5.2342 Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:taprio_set_budgets+0x1a7/0x3b0 net/sched/sch_taprio.c:674 Code: 8b 3f 48 89 ef 4c 89 fe e8 96 ad 23 f8 4c 39 fd 75 13 e8 2c ab 23 f8 41 bd ff ff ff 7f 4d 89 f7 e9 9c 00 00 00 e8 19 ab 23 f8 <4c> 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 4d RSP: 0018:ffffc90000007c00 EFLAGS: 00000006 RAX: ffffffff899c08a7 RBX: 0000000000000000 RCX: ffff888031df8000 RDX: 0000000000010000 RSI: 0000000004000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f7c R12: 0000000000000000 R13: ffff888028188c00 R14: ffff888028188c00 R15: 0000000004000001 FS: 00007f1761a006c0(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c38b814 CR3: 000000001bec2000 CR4: 00000000003526f0 Call Trace: advance_sched+0x963/0xc90 net/sched/sch_taprio.c:982 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:747 [inline] RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:750 Code: e8 bf 5b 5a 03 eb cc 66 66 66 66 2e 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 41 57 <41> 56 53 65 ff 05 50 51 fa 10 e8 bb a2 d4 09 89 c3 83 f8 08 73 65 RSP: 0018:ffffc90003a7f5b0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffffff822e64aa RCX: 0000000000080000 RDX: ffffc9000b3c9000 RSI: ffffffff822e64aa RDI: ffffffff8e139fa0 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822e64aa R10: dffffc0000000000 R11: fffff940002866d9 R12: dffffc0000000000 R13: ffffffff822e64aa R14: ffffffff8e139fa0 R15: ffff88813fffa540 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock_sched include/linux/rcupdate.h:953 [inline] pfn_valid+0x3b2/0x490 include/linux/mmzone.h:2172 page_table_check_set+0x25/0x730 mm/page_table_check.c:105 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline] set_ptes include/linux/pgtable.h:292 [inline] set_pte_range+0x6a5/0x700 mm/memory.c:5313 finish_fault+0xcbf/0x1080 mm/memory.c:5437 do_read_fault mm/memory.c:5577 [inline] do_fault mm/memory.c:5707 [inline] do_pte_missing mm/memory.c:4234 [inline] handle_pte_fault mm/memory.c:6052 [inline] __handle_mm_fault+0x3643/0x5440 mm/memory.c:6195 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6364 faultin_page mm/gup.c:1144 [inline] __get_user_pages+0x1699/0x2ce0 mm/gup.c:1446 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1880 __mm_populate+0x24c/0x380 mm/gup.c:1983 mm_populate include/linux/mm.h:3374 [inline] vm_mmap_pgoff+0x387/0x4d0 mm/util.c:585 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1760b8ebe9 Code: 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 01 48 RSP: 002b:00007f1761a00038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f1760db5fa0 RCX: 00007f1760b8ebe9 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f1760c11e19 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1760db6038 R14: 00007f1760db5fa0 R15: 00007ffeda1a3d98 rcu: rcu_preempt kthread starved for 10490 jiffies! g80673 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: CPU: 1 UID: 0 PID: 8584 Comm: kworker/u8:17 Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 5e RSP: 0018:ffffc9001a7f7660 EFLAGS: 00000293 RAX: ffffffff81b4557b RBX: 1ffff110170c8341 RCX: ffff888027278000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9001a7f77e0 R08: ffffffff8fa39a37 R09: 1ffffffff1f47346 R10: dffffc0000000000 R11: fffffbfff1f47347 R12: ffff8880b8641a08 R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd2bb7ff000 CR3: 000000000df36000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245