rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=0bdc/1/0x4000000000000000 softirq=24218/24234 fqs=5 rcu: (detected by 0, t=10502 jiffies, g=22497, q=1264 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6473 Comm: rm Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:advance_sched+0x581/0xc80 net/sched/sch_taprio.c:970 Code: 89 df 4c 89 f6 e8 0f ac e8 f7 4c 39 f3 75 1b e8 a5 a9 e8 f7 48 bb ff ff ff ff ff ff ff 7f 49 be 00 00 00 00 00 fc ff df eb 43 8a a9 e8 f7 49 be 00 00 00 00 00 fc ff df 48 8b 44 24 48 42 80 RSP: 0018:ffffc90000a08d10 EFLAGS: 00000093 RAX: ffffffff89de6a51 RBX: 0000000000000000 RCX: ffff888052673e00 RDX: 0000000000010000 RSI: 00000000000000ff RDI: 0000000000000000 RBP: ffff888056439000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000141190 R12: 1ffff1100ac87200 R13: 0000000000000000 R14: 00000000000000ff R15: ffff8880564390c0 FS: 0000000000000000(0000) GS:ffff88812504f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d44112440 CR3: 0000000036eea000 CR4: 00000000003526f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:filter_irq_stacks+0x78/0xa0 kernel/stacktrace.c:-1 Code: 81 0f 92 c2 84 d1 75 27 48 3d 40 1b d5 8b 0f 92 c1 48 3d 5b 1b d5 8b 0f 93 c0 08 c8 74 11 48 ff c3 49 83 c7 08 49 39 dc 75 ae <44> 89 e3 eb 06 ff c3 eb 02 31 db 89 d8 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000349e348 EFLAGS: 00000246 RAX: ffffffff81000101 RBX: 0000000000000010 RCX: 0000000000000001 RDX: 0000000000002901 RSI: 0000000000000010 RDI: ffffc9000349e3d0 RBP: ffffc9000349e5f8 R08: ffffffff81d765a6 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000010 R13: dffffc0000000000 R14: ffffc9000349e3d0 R15: ffffc9000349e450 stack_depot_save_flags+0x33/0x800 lib/stackdepot.c:667 kasan_save_stack mm/kasan/common.c:58 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_flags_noprof+0x52d/0x800 mm/slub.c:5528 _kmalloc_flags_noprof mm/slab.h:39 [inline] __alloc_empty_sheaf mm/slub.c:2751 [inline] alloc_empty_sheaf mm/slub.c:2771 [inline] __kfree_rcu_sheaf+0x3c4/0x5e0 mm/slub.c:6074 kfree_rcu_sheaf mm/slab_common.c:1625 [inline] kvfree_call_rcu+0x9f/0x430 mm/slab_common.c:1974 ma_free_rcu lib/maple_tree.c:173 [inline] mas_free lib/maple_tree.c:1153 [inline] mas_replace_node lib/maple_tree.c:1595 [inline] mas_wr_node_store lib/maple_tree.c:3201 [inline] mas_wr_store_entry+0x5351/0x80c0 lib/maple_tree.c:3531 mas_store_prealloc+0x63b/0xa30 lib/maple_tree.c:4936 vma_iter_store_new mm/vma.h:623 [inline] vma_complete+0x211/0x9a0 mm/vma.c:359 __split_vma+0x8fa/0xa50 mm/vma.c:569 vms_gather_munmap_vmas+0x4e3/0x1370 mm/vma.c:1448 __mmap_setup mm/vma.c:2439 [inline] __mmap_region mm/vma.c:2756 [inline] mmap_region+0x8f9/0x2310 mm/vma.c:2860 do_mmap+0xc3b/0x10c0 mm/mmap.c:560 vm_mmap_pgoff+0x272/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:606 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d443f4242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007ffc521e38c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f0d44108000 RCX: 00007f0d443f4242 RDX: 0000000000000001 RSI: 0000000000002000 RDI: 00007f0d44108000 RBP: 0000000000000812 R08: 0000000000000003 R09: 000000000000b000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc521e3950 R13: 00007f0d443c9580 R14: 00007ffc521e3d40 R15: 00000fff8a43c71c rcu: rcu_preempt kthread starved for 10492 jiffies! g22497 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:26848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 76 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x11e6/0x15f0 kernel/smp.c:912 Code: c0 75 7a 41 8b 1e 89 de 83 e6 01 31 ff e8 e2 22 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1e 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 73 1e 0c RSP: 0018:ffffc9000228f700 EFLAGS: 00000293 RAX: ffffffff81baf58d RBX: dffffc0000000000 RCX: ffff88801e381f00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000228f860 R08: ffffffff9057a637 R09: 1ffffffff20af4c6 R10: dffffc0000000000 R11: fffffbfff20af4c7 R12: 1ffff110170e81d1 R13: ffff8880b863c448 R14: ffff8880b8740e88 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124f4f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e47b38040 CR3: 000000000e946000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:911 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245