rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P27390/1:b..l P27392/1:b..l rcu: (detected by 1, t=10502 jiffies, g=205557, q=1680 ncpus=2) task:dhcpcd-run-hook state:R running task stack:25504 pid:27392 tgid:27392 ppid:27367 task_flags:0x400040 flags:0x00080800 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 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:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x513/0x23d0 arch/x86/kernel/unwind_orc.c:510 Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 RSP: 0000:ffffc9000c6bf238 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffffffff8fc500d4 RCX: dffffc0000000000 RDX: ffffffff8fc500d4 RSI: ffffffff90465c00 RDI: ffffffff8be09d00 RBP: ffffffff8fc500d4 R08: 0000000000000001 R09: ffffffff8e144f60 R10: ffffc9000c6bf358 R11: ffffffff81ad18d0 R12: ffffffff823befed R13: ffffffff8fc500d4 R14: ffffc9000c6bf308 R15: ffffffff8fc500d4 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 slab_free_hook mm/slub.c:2517 [inline] slab_free mm/slub.c:6690 [inline] kmem_cache_free+0x475/0x620 mm/slub.c:6801 exit_mmap+0x52c/0xb10 mm/mmap.c:1302 __mmput+0x118/0x430 kernel/fork.c:1177 exec_mmap+0x569/0x6f0 fs/exec.c:893 begin_new_exec+0x1353/0x2440 fs/exec.c:1148 load_elf_binary+0x998/0x2740 fs/binfmt_elf.c:1010 search_binary_handler fs/exec.c:1664 [inline] exec_binprm fs/exec.c:1696 [inline] bprm_execve+0x92e/0x1400 fs/exec.c:1748 do_execveat_common+0x478/0x6e0 fs/exec.c:1847 do_execve fs/exec.c:1902 [inline] __do_sys_execve fs/exec.c:1978 [inline] __se_sys_execve fs/exec.c:1973 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:1973 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: 0033:0x7fec91135107 RSP: 002b:00007ffd1bc711e8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00005561f92be1a8 RCX: 00007fec91135107 RDX: 00005561f92b9e28 RSI: 00005561f92be1a8 RDI: 00005561f92b9eb0 RBP: 00005561f92b9eb0 R08: 00007ffd1bc75e57 R09: 0000000000000210 R10: 0000000000000002 R11: 0000000000000246 R12: 00005561f92b9e28 R13: 00007fec912fae8b R14: 00005561f92b9e28 R15: 0000000000000000 task:syz.7.4623 state:R running task stack:21312 pid:27390 tgid:27390 ppid:18043 task_flags:0x400640 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 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:__orc_find arch/x86/kernel/unwind_orc.c:100 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x2ab/0x23d0 arch/x86/kernel/unwind_orc.c:510 Code: 00 45 39 e8 48 bd 00 00 00 00 00 fc ff df 0f 84 1c 04 00 00 4a 8d 14 ad 14 a9 b4 8f 45 29 e8 4a 8d 1c 82 48 83 c3 fc 49 89 d5 <48> 39 da 0f 86 21 02 00 00 49 29 d5 49 c1 fd 02 4a 8d 04 6d 00 00 RSP: 0018:ffffc9000c6cdf98 EFLAGS: 00000293 RAX: ffffffff90448f6e RBX: ffffffff8fc3cdc4 RCX: 0000000080000000 RDX: ffffffff8fc3cdc4 RSI: ffffffff90448f68 RDI: ffffffff8be09d00 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8e144f60 R10: ffffc9000c6ce0b8 R11: ffffffff81ad18d0 R12: ffffffff8224f501 R13: ffffffff8fc3cdc4 R14: ffffc9000c6ce068 R15: 00000000000124f5 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:165 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x23d/0x2a0 mm/page_alloc.c:1887 prep_new_page mm/page_alloc.c:1895 [inline] get_page_from_freelist+0x23a5/0x2440 mm/page_alloc.c:3948 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5236 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2505 shmem_alloc_folio mm/shmem.c:1903 [inline] shmem_alloc_and_add_folio+0x423/0xf40 mm/shmem.c:1945 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2540 shmem_get_folio mm/shmem.c:2646 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3299 generic_perform_write+0x2c5/0x900 mm/filemap.c:4314 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3474 __kernel_write_iter+0x428/0x910 fs/read_write.c:621 dump_emit_page fs/coredump.c:1298 [inline] dump_user_range+0x8a0/0xc90 fs/coredump.c:1372 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: 0033:0x7ff23598f751 RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007ff235be6090 RCX: 00007ff23598f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007ff235a13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff235be6128 R14: 00007ff235be6090 R15: 00007fff115eeb98 rcu: rcu_preempt kthread starved for 10537 jiffies! g205557 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:27656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 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: 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: cc cc cc cc 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 e3 3f 29 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 000002c2 RAX: 0000000002abf51d RBX: ffffffff81977eae RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d9a99b4 RDI: ffffffff8be09d60 RBP: ffffc90000197f10 R08: ffff8880b873375b R09: 1ffff110170e66eb R10: dffffc0000000000 R11: ffffed10170e66ec R12: ffffffff8fa2d8f0 R13: 1ffff11003ad4b58 R14: 0000000000000001 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125cf7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34a1eff8 CR3: 0000000027f92000 CR4: 00000000003526f0 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