rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...0: (0 ticks this GP) idle=f0ec/1/0x4000000000000000 softirq=95237/95241 fqs=2020 rcu: hardirqs softirqs csw/system rcu: number: 0 0 0 rcu: cputime: 0 0 0 ==> 52500(ms) rcu: (detected by 1, t=10502 jiffies, g=69469, q=566 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17904 Comm: syz.8.2314 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:advance_sched+0x3dc/0xc80 net/sched/sch_taprio.c:960 Code: 89 f8 48 c1 e8 03 80 3c 08 00 0f 85 41 07 00 00 49 89 9f c0 00 00 00 41 83 c6 01 44 89 ee 49 83 c7 08 44 89 f7 e8 34 38 21 f8 <45> 39 ee 0f 84 ee 00 00 00 e8 a6 3d 21 f8 4d 63 e6 49 83 fc 0f 0f RSP: 0018:ffffc90000007d90 EFLAGS: 00000046 RAX: 0000000080010002 RBX: 1864a2ad5928a9d0 RCX: ffffffff899aa8fc RDX: ffff88801fb3c880 RSI: 0000000000000002 RDI: 0000000000000004 RBP: 0000000004000001 R08: 0000000000000004 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000002 R14: 0000000000000002 R15: ffff88805caab010 FS: 0000000000000000(0000) GS:ffff888124718000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2c452f CR3: 0000000088f51000 CR4: 00000000003526f0 Call Trace: __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+0x108/0x3f0 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:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:217 Code: 8b 05 69 99 14 12 a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 3c 16 00 00 85 c0 74 2b <8b> 82 18 16 00 00 83 f8 02 75 20 48 8b 8a 20 16 00 00 8b 92 1c 16 RSP: 0018:ffffc9000e157760 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000001 RCX: ffffffff822e6b5d RDX: ffff88801fb3c880 RSI: ffffffff822e6e4d RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88801d82af30 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000897 rcu_read_unlock include/linux/rcupdate.h:869 [inline] page_table_check_clear+0x62d/0x740 mm/page_table_check.c:89 __page_table_check_pte_clear+0xf1/0x100 mm/page_table_check.c:154 page_table_check_pte_clear include/linux/page_table_check.h:51 [inline] ptep_get_and_clear_full arch/x86/include/asm/pgtable.h:1317 [inline] get_and_clear_full_ptes include/linux/pgtable.h:714 [inline] zap_present_folio_ptes mm/memory.c:1505 [inline] zap_present_ptes mm/memory.c:1590 [inline] do_zap_pte_range mm/memory.c:1691 [inline] zap_pte_range mm/memory.c:1735 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x24bd/0x4350 mm/memory.c:1898 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1941 unmap_vmas+0x218/0x470 mm/memory.c:1985 exit_mmap+0x1b9/0xb90 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1121 mmput+0x62/0x70 kernel/fork.c:1144 exit_mm kernel/exit.c:581 [inline] do_exit+0x7c4/0x2bd0 kernel/exit.c:952 do_group_exit+0xd3/0x2a0 kernel/exit.c:1105 __do_sys_exit_group kernel/exit.c:1116 [inline] __se_sys_exit_group kernel/exit.c:1114 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1114 x64_sys_call+0x1530/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f1850f8e929 Code: Unable to access opcode bytes at 0x7f1850f8e8ff. RSP: 002b:00007fffe891d6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1850f8e929 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffe891d72c R08: 0000001ee891d7bf R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000de R13: 00000000000927c0 R14: 00000000000953ad R15: 00007fffe891d780 rcu: rcu_preempt kthread starved for 400 jiffies! g69469 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:28152 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6883 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: eb 6b 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 f0 21 00 fb f4 0c fb 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000001e9c267 RBX: 0000000000000001 RCX: ffffffff8b881c69 RDX: 0000000000000000 RSI: ffffffff8de3106c RDI: ffffffff8c158660 RBP: ffffed1003cd6488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e6b2440 R14: ffffffff90a97350 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124818000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555da425c8 CR3: 0000000075b0a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148