rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6610/1:b.el rcu: (detected by 1, t=10504 jiffies, g=21225, q=2815 ncpus=2) task:modprobe state:R running task stack:24776 pid:6610 tgid:6610 ppid:12 task_flags:0x400000 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:23 [inline] RIP: 0010:lock_acquire+0x61/0x350 kernel/locking/lockdep.c:5831 Code: 24 58 0f 1f 44 00 00 65 8b 05 2f 6c ca 11 83 f8 08 0f 83 83 01 00 00 89 c0 48 0f a3 05 18 dd b4 0e 73 0d e8 f1 29 09 00 84 c0 <0f> 84 ca 01 00 00 83 3d 12 10 b5 0e 00 0f 84 d3 00 00 00 48 8b b4 RSP: 0018:ffffc9000ffeedc0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8c4bdc60 RDI: ffffffff8c4bdc20 RBP: ffffffff8177827f R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff81b1fa10 R12: 0000000000000002 R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_pages_mpol+0x212/0x380 mm/mempolicy.c:2490 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline] alloc_pages_noprof+0xac/0x2a0 mm/mempolicy.c:2581 pagetable_alloc_noprof include/linux/mm.h:3685 [inline] __pud_alloc_one_noprof include/asm-generic/pgalloc.h:181 [inline] pud_alloc_one_noprof include/asm-generic/pgalloc.h:206 [inline] __pud_alloc+0x3a/0x460 mm/memory.c:6748 pud_alloc include/linux/mm.h:3595 [inline] __handle_mm_fault mm/memory.c:6439 [inline] handle_mm_fault+0x1f85/0x3080 mm/memory.c:6686 do_user_addr_fault+0x744/0x1340 arch/x86/mm/fault.c:1394 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0010:__clear_user arch/x86/include/asm/uaccess_64.h:190 [inline] RIP: 0010:clear_user arch/x86/include/asm/uaccess_64.h:207 [inline] RIP: 0010:padzero fs/binfmt_elf.c:134 [inline] RIP: 0010:elf_load+0x4b7/0x6a0 fs/binfmt_elf.c:436 Code: 8d 6f 20 eb 7a 41 be 00 10 00 00 4d 29 ee 48 c7 c7 d6 22 26 8e be b7 00 00 00 e8 34 2c b4 ff 0f 01 cb 31 c0 4c 89 e7 4c 89 f1 aa 0f 1f 00 49 89 ce 0f 01 ca 31 ff 48 89 ce e8 54 57 5f ff 8b RSP: 0018:ffffc9000ffefa08 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 00005574c2550010 RCX: 0000000000000ff8 RDX: 0000000000000000 RSI: ffffffff8e4b28e4 RDI: 00005574c2550008 RBP: dffffc0000000000 R08: ffffffff821bde4f R09: 0000000000000000 R10: 0000000000000000 R11: ffff88801b057678 R12: 00005574c2550008 R13: 0000000000000008 R14: 0000000000000ff8 R15: ffff888031713918 load_elf_binary+0x116f/0x2950 fs/binfmt_elf.c:1188 search_binary_handler fs/exec.c:1694 [inline] exec_binprm fs/exec.c:1726 [inline] bprm_execve+0x9c7/0x1630 fs/exec.c:1778 kernel_execve+0x8c3/0x9c0 fs/exec.c:1922 call_usermodehelper_exec_async+0x20f/0x360 kernel/umh.c:109 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: rcu_preempt kthread timer wakeup didn't happen for 10503 jiffies! g21225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=5852 rcu: rcu_preempt kthread starved for 10504 jiffies! g21225 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27496 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5614 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:qdisc_dev include/net/sch_generic.h:612 [inline] RIP: 0010:taprio_set_budgets+0x60/0x3a0 net/sched/sch_taprio.c:666 Code: 80 3c 20 00 74 08 4c 89 ff e8 dc 6f 56 f8 4d 8b 3f 49 83 c7 40 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 4c 89 ff e8 b6 6f 56 f8 4d 8b 3f 4c 89 f8 48 c1 e8 03 48 b9 RSP: 0018:ffffc90000007ca8 EFLAGS: 00000046 RAX: 1ffff110036f2008 RBX: ffff88801b790280 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: ffff8880546e2800 RDI: ffff88801b790280 RBP: ffff8880546e2800 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f90 R12: dffffc0000000000 R13: ffff88801b790000 R14: ffff88801b790280 R15: ffff88801b790040 FS: 0000000000000000(0000) GS:ffff888124f4e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005574c2550008 CR3: 0000000033a3b000 CR4: 0000000000350ef0 Call Trace: advance_sched+0x970/0xc80 net/sched/sch_taprio.c:984 __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:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 54 bc 88 0c 48 89 de 5b e9 23 0b 62 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d f8 1b a6 11 65 8b 15 19 1c a6 11 81 e2 00 01 ff 00 74 RSP: 0018:ffffc90003167358 EFLAGS: 00000246 RAX: ffffffff8219923e RBX: ffff8880330da640 RCX: ffff888035e08000 RDX: 8000000057fad027 RSI: 00007fce38da6000 RDI: ffff8880705778c0 RBP: ffffc90003167690 R08: ffffea00015feb33 R09: 1ffffd40002bfd66 R10: dffffc0000000000 R11: fffff940002bfd67 R12: dffffc0000000000 R13: ffff8880705778c0 R14: ffff88807057bd30 R15: 8000000057fad027 vm_normal_page+0x1e/0x280 mm/memory.c:769 zap_present_ptes mm/memory.c:1700 [inline] do_zap_pte_range mm/memory.c:1832 [inline] zap_pte_range mm/memory.c:1934 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x1091/0x4f10 mm/memory.c:2109 unmap_vmas+0x390/0x550 mm/memory.c:2178 exit_mmap+0x293/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fce39b59017 Code: Unable to access opcode bytes at 0x7fce39b58fed. RSP: 002b:00007ffced3ee2b0 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000055555c66f500 RCX: 00007fce39b59017 RDX: 0000000040000000 RSI: 00007ffced3ee30c RDI: ffffffffffffffff RBP: 00007ffced3ee30c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffced3ee568 R15: 0000000000000000