rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=dec4/1/0x4000000000000000 softirq=40320/40323 fqs=8 rcu: (detected by 1, t=10502 jiffies, g=29721, q=641 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9461 Comm: syz.2.1132 Not tainted 6.14.0-syzkaller-12966-ga2cc6ff5ec8f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:advance_sched+0x62e/0xca0 net/sched/sch_taprio.c:-1 Code: 48 89 ef e8 74 05 07 f8 4b 89 9c fe c0 00 00 00 4c 39 bc 24 90 00 00 00 0f 84 21 01 00 00 e8 e9 df 9c f7 48 83 c5 08 49 ff c7 e9 fe ff ff 48 c7 c7 40 94 15 90 4d 89 fd 4c 89 fe e8 db 23 1a RSP: 0018:ffffc90000007c70 EFLAGS: 00000002 RAX: ffffffff8a267797 RBX: 1839914e28000000 RCX: ffff888027d20000 RDX: 0000000000010000 RSI: 0000000004000000 RDI: 0000000000000000 RBP: ffff88807cdb84c8 R08: ffffffff8a2676f3 R09: fffff52000000f7c R10: dffffc0000000000 R11: fffff52000000f7c R12: dffffc0000000000 R13: ffff88807cdb8400 R14: ffff88807cdb8400 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124f99000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3081dff8 CR3: 0000000046736000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1791 [inline] __hrtimer_run_queues+0x5a8/0xd40 kernel/time/hrtimer.c:1855 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1917 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:736 Code: 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 d0 ba bf 11 e8 db 89 87 0a <89> c3 83 f8 08 73 7a 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 RSP: 0018:ffffc900045e7428 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888027d20000 RDX: ffff888027d20000 RSI: ffffffff8ca1b120 RDI: ffffffff8ca1b0e0 RBP: ffffffff82394ee8 R08: ffffffff82394f18 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff11005fb59fc R13: ffffea00017d8740 R14: 0000000000000001 R15: 0000000000000000 rcu_read_lock include/linux/rcupdate.h:842 [inline] page_table_check_clear+0x1a1/0x6f0 mm/page_table_check.c:77 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:714 [inline] zap_present_folio_ptes mm/memory.c:1501 [inline] zap_present_ptes mm/memory.c:1586 [inline] do_zap_pte_range mm/memory.c:1687 [inline] zap_pte_range mm/memory.c:1731 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x33cf/0x44d0 mm/memory.c:1894 unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984 exit_mmap+0x2bc/0xde0 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe45398d169 Code: Unable to access opcode bytes at 0x7fe45398d13f. RSP: 002b:00007ffeee529fe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe45398d169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffeee52a04c R08: 00000004ee52a0df R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000d7 R13: 00000000000927c0 R14: 000000000003e410 R15: 00007ffeee52a0a0 rcu: rcu_preempt kthread starved for 10486 jiffies! g29721 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:26376 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 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: 9448 Comm: syz.3.1128 Not tainted 6.14.0-syzkaller-12966-ga2cc6ff5ec8f #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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: 8b 3d d4 2c b6 0c 48 89 de 5b e9 c3 b1 5e 00 0f 1f 00 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 0c 25 08 70 68 93 65 8b 15 98 18 a5 11 81 e2 00 01 ff 00 RSP: 0018:ffffc90004617378 EFLAGS: 00000202 RAX: ffffffff81b7792d RBX: 1ffff110170c823d RCX: ffff88802adc3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90004617580 R08: ffffffff81b778f8 R09: 1ffffffff20bf9ee R10: dffffc0000000000 R11: fffffbfff20bf9ef R12: ffff8880b873ad08 R13: ffff8880b86411e8 R14: ffff8880b873ad00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125099000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f07f3c546a8 CR3: 000000005d378000 CR4: 0000000000350ef0 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x1bcd/0x2d40 kernel/smp.c:885 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline] flush_tlb_mm_range+0xb8d/0x13f0 arch/x86/mm/tlb.c:1365 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu+0x1aa/0x690 mm/mmu_gather.c:403 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:496 exit_mmap+0x5b1/0xde0 mm/mmap.c:1297 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd34858d169 Code: Unable to access opcode bytes at 0x7fd34858d13f. RSP: 002b:00007fd349424038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: fffffffffffffe00 RBX: 00007fd3487a5fa0 RCX: 00007fd34858d169 RDX: 0000200000000040 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007fd34860e2a0 R08: 0000200000000080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd3487a5fa0 R15: 00007ffe9558d978