rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=c6ec/1/0x4000000000000000 softirq=24667/24667 fqs=0 rcu: (detected by 1, t=10503 jiffies, g=25997, q=432 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8539 Comm: syz.3.1160 Not tainted 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:65 Code: d8 38 f5 e8 12 60 3b f5 eb a8 e8 ab e0 ff ff 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 90 0f 1e fa 48 89 fe 48 c7 c7 80 b7 5f 8c e9 bd fe ff ff 66 2e 0f RSP: 0018:ffffc90000007b18 EFLAGS: 00000046 RAX: ffffffff93e36710 RBX: 0000000000000046 RCX: ffffffff819ad130 RDX: 0000000000000000 RSI: ffffffff8c5fb760 RDI: ffffffff8c0ab420 RBP: ffffc90000007c60 R08: ffffffff901a3377 R09: 1ffffffff203466e R10: dffffc0000000000 R11: fffffbfff203466f R12: 1ffff92000000f70 R13: ffffffff89ef5942 R14: ffffc90000007bd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fb1eff8 CR3: 000000000e738000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:464 [inline] lock_release+0x1bc/0xa30 kernel/locking/lockdep.c:5871 rcu_lock_release include/linux/rcupdate.h:347 [inline] rcu_read_unlock include/linux/rcupdate.h:880 [inline] advance_sched+0xb32/0xca0 net/sched/sch_taprio.c:987 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x59b/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5855 Code: 2b 00 74 08 4c 89 f7 e8 1a b6 88 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003ab7300 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000756e6c RCX: ffff88801e68c6e8 RDX: dffffc0000000000 RSI: ffffffff8c0ab8e0 RDI: ffffffff8c5fb780 RBP: ffffc90003ab7458 R08: ffffffff942c6847 R09: 1ffffffff2858d08 R10: dffffc0000000000 R11: fffffbfff2858d09 R12: 1ffff92000756e68 R13: dffffc0000000000 R14: ffffc90003ab7360 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 page_table_check_clear+0x4b/0x550 mm/page_table_check.c:74 get_and_clear_full_ptes include/linux/pgtable.h:712 [inline] zap_present_folio_ptes mm/memory.c:1511 [inline] zap_present_ptes mm/memory.c:1596 [inline] do_zap_pte_range mm/memory.c:1698 [inline] zap_pte_range mm/memory.c:1740 [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+0x376d/0x48d0 mm/memory.c:1894 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1984 exit_mmap+0x283/0xd40 mm/mmap.c:1284 __mmput+0x115/0x410 kernel/fork.c:1356 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9ad/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbb6918cde9 Code: Unable to access opcode bytes at 0x7fbb6918cdbf. RSP: 002b:00007fff4ae84088 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbb6918cde9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff4ae840ec R08: 000000044ae8417f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000010a R13: 00000000000927c0 R14: 000000000002c18a R15: 00007fff4ae84140 rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g25997 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=13010 rcu: rcu_preempt kthread starved for 10503 jiffies! g25997 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:24144 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244