rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P15145/3:b..l P15211/1:b..l rcu: (detected by 0, t=10502 jiffies, g=66349, q=561 ncpus=2) task:dhcpcd-run-hook state:R running task stack:28088 pid:15211 tgid:15211 ppid:15204 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d8/0x3b0 kernel/locking/lockdep.c:5893 Code: 33 e2 10 00 00 00 00 eb b5 e8 44 9f bb 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 34 ee e1 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 04 1f 72 ff cc 48 8d 3d d1 4a e7 RSP: 0018:ffffc90004e8f8b0 EFLAGS: 00000282 RAX: d31ff316429d7e00 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8d976a7d RDI: ffffffff8bc08660 RBP: ffff888076ec4830 R08: ffffffff8241f08c R09: ffffffff8df41aa0 R10: dffffc0000000000 R11: ffffed10045cb366 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8df41aa0 R15: ffff888076ec3d00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] mntput_no_expire+0x190/0x1c0 fs/namespace.c:1409 path_put fs/namei.c:666 [inline] terminate_walk+0x2ba/0x3f0 fs/namei.c:796 path_lookupat+0x74f/0x8c0 fs/namei.c:2771 filename_lookup+0x212/0x570 fs/namei.c:2783 vfs_statx+0xf8/0x550 fs/stat.c:353 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8f49b78b0a RSP: 002b:00007ffdb6416638 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f8f49b78b0a RDX: 00007ffdb6416648 RSI: 0000562c7763df08 RDI: 00000000ffffff9c RBP: 0000562c77634130 R08: 0000000000000001 R09: 3c00000040001201 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8f49d00322 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 task:syz.7.2036 state:R running task stack:22592 pid:15145 tgid:15145 ppid:7625 task_flags:0x400640 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047 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+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0x192d/0x1fd0 mm/filemap.c:3931 do_fault_around mm/memory.c:5713 [inline] do_read_fault mm/memory.c:5746 [inline] do_fault mm/memory.c:5889 [inline] do_pte_missing+0x20b0/0x3330 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0x1b26/0x32b0 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1650/0x29f0 mm/gup.c:1428 __get_user_pages_locked mm/gup.c:1692 [inline] get_dump_page+0x1ac/0x3f0 mm/gup.c:2192 dump_user_range+0x1de/0xc90 fs/coredump.c:1366 elf_core_dump+0x3369/0x3960 fs/binfmt_elf.c:2111 coredump_write+0x1121/0x18b0 fs/coredump.c:1049 do_coredump fs/coredump.c:1126 [inline] vfs_coredump+0x3321/0x3e60 fs/coredump.c:1200 get_signal+0x1108/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop kernel/entry/common.c:75 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0x178/0x670 kernel/entry/common.c:196 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fd28738f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fd2875e6090 RCX: 00007fd28738f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fd287413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fd2875e6128 R14: 00007fd2875e6090 R15: 00007ffd6a711818 rcu: rcu_preempt kthread starved for 10580 jiffies! g66349 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:27008 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 1e 84 b6 f5 cc cc cc 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 53 91 0e 00 f3 0f 1e fa fb f4 f3 83 b6 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 000002c6 RAX: 00000000017e9771 RBX: ffffffff8197142e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d792d26 RDI: ffffffff8bc08660 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8f822470 R13: 1ffff1100385fb70 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5df3a4295f CR3: 0000000031553000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147