rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9526/1:b..l P9524/1:b..l rcu: (detected by 1, t=10502 jiffies, g=30737, q=2981 ncpus=2) task:dhcpcd state:R running task stack:24360 pid:9524 tgid:9524 ppid:5499 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x19e/0x23b0 arch/x86/kernel/unwind_orc.c:-1 Code: 24 24 4d 8d 74 24 35 4c 89 f5 48 c1 ed 03 42 0f b6 44 2d 00 84 c0 0f 85 7d 1a 00 00 4d 0f be 26 48 8b 44 24 38 42 80 3c 28 00 <48> 8b 5c 24 10 74 08 48 89 df e8 43 5a bf 00 4c 03 23 49 ff cc 4c RSP: 0018:ffffc900032d7528 EFLAGS: 00000246 RAX: 1ffff9200065aec9 RBX: 0000000000000000 RCX: ffff88805b238000 RDX: 0000000000000000 RSI: ffffffff8ca1b660 RDI: ffffffff8ca1b620 RBP: 1ffff9200065aec6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc900032d7635 R15: ffffffff816d9bc8 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbf/0xd0 mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2359 [inline] slab_free mm/slub.c:4656 [inline] kmem_cache_free+0x2ff/0x410 mm/slub.c:4758 remove_vma mm/vma.c:430 [inline] vms_complete_munmap_vmas+0x655/0x8f0 mm/vma.c:1249 do_vmi_align_munmap+0x5b9/0x6c0 mm/vma.c:1492 do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1540 __vm_munmap+0x37b/0x520 mm/vma.c:3013 __do_sys_munmap mm/mmap.c:1084 [inline] __se_sys_munmap mm/mmap.c:1081 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbba8471b97 RSP: 002b:00007ffce8451458 EFLAGS: 00000202 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000557f9211b3c0 RCX: 00007fbba8471b97 RDX: 0000000000000001 RSI: 0000000000023910 RDI: 00007fbba826f000 RBP: 00007ffce8451550 R08: 0000000000000000 R09: 0f55154aa43e12f0 R10: 00007ffce84513e0 R11: 0000000000000202 R12: 00007fbba8485000 R13: 0000000000000000 R14: 0000557f9211b3c0 R15: 0000000000000000 task:syz.6.993 state:R running task stack:24936 pid:9526 tgid:9526 ppid:6454 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1761 [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+0x39c5/0x44d0 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+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffa3c58e169 RSP: 002b:00007ffdf9473f68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffa3c58e169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdf9473fcc R08: 00000004f947405f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000088 R13: 00000000000927c0 R14: 000000000003e528 R15: 00007ffdf9474020 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g30737 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=18250 rcu: rcu_preempt kthread starved for 10502 jiffies! g30737 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:26688 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 9531 Comm: syz.4.992 Not tainted 6.15.0-rc2-syzkaller-00493-gac71fabf1567 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__hrtimer_run_queues+0x25d/0xd40 kernel/time/hrtimer.c:1822 Code: 90 00 00 00 48 89 44 24 18 49 8d 04 1f 48 05 88 00 00 00 48 89 84 24 90 00 00 00 4c 8b 64 24 20 48 8b 44 24 50 42 80 3c 28 00 <74> 0d 48 8d bc 24 e0 00 00 00 e8 d4 ea 7c 00 4c 8b bc 24 e0 00 00 RSP: 0018:ffffc90000007d40 EFLAGS: 00000046 RAX: 1ffff92000000fc4 RBX: ffff8880b8627908 RCX: ffff88802a799e00 RDX: 0000000000010000 RSI: 1ffff110170c4f1a RDI: ffff8880797de340 RBP: ffffc90000007ea0 R08: ffff8880797de357 R09: ffff8880797de340 R10: dffffc0000000000 R11: ffffed100f2fbc6b R12: 1ffff110170c4f23 R13: dffffc0000000000 R14: ffff8880797de340 R15: ffff8880b86276c0 FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3261eff8 CR3: 00000000316fc000 CR4: 0000000000350ef0 Call Trace: hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 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:_compound_head include/linux/page-flags.h:280 [inline] RIP: 0010:__folio_rmap_sanity_checks+0xdf/0x710 include/linux/rmap.h:426 Code: e7 20 a8 ff bf 01 00 00 00 44 89 f6 e8 1a 25 a8 ff 45 85 f6 0f 8e 66 03 00 00 e8 cc 20 a8 ff 49 8d 5d 08 48 89 d8 48 c1 e8 03 <48> b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 89 5a RSP: 0018:ffffc90003b2f3e0 EFLAGS: 00000212 RAX: 1ffffd40003ae589 RBX: ffffea0001d72c48 RCX: ffff88802a799e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00000000000136c4 R08: ffffffff821a9c46 R09: 1ffffd40003ae588 R10: dffffc0000000000 R11: fffff940003ae589 R12: ffffea0001d72c40 R13: ffffea0001d72c40 R14: 0000000000000001 R15: 0000000000000000 __folio_remove_rmap mm/rmap.c:1694 [inline] folio_remove_rmap_ptes+0x3d/0xa70 mm/rmap.c:1804 zap_present_folio_ptes mm/memory.c:1525 [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+0x21cf/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+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa9f658e169 Code: Unable to access opcode bytes at 0x7fa9f658e13f. RSP: 002b:00007ffc87c89bf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa9f658e169 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc87c89c5c R08: 0000000487c89cef R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000002 R13: 00000000000927c0 R14: 000000000003e4e7 R15: 00007ffc87c89cb0