rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16773/3:b..l rcu: (detected by 0, t=10503 jiffies, g=89201, q=403 ncpus=2) task:dhcpcd-run-hook state:R running task stack:28088 pid:16773 tgid:16773 ppid:16739 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_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 do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f96161c0636 RSP: 002b:00007fff36793d20 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00007fff36793d28 RCX: 00007f96161c0636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000558dd7c30c30 R08: 0000000000000000 R09: 3c00000040001201 R10: 00007f9616026f50 R11: 0000000000000246 R12: 0000558dd7c3e910 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10529 jiffies! g89201 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27264 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: CPU: 0 UID: 0 PID: 16742 Comm: syz.9.2207 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:orc_find arch/x86/kernel/unwind_orc.c:229 [inline] RIP: 0010:unwind_next_frame+0x223/0x23d0 arch/x86/kernel/unwind_orc.c:510 Code: 86 78 04 00 00 44 89 f8 4c 8d 2c 85 00 20 c2 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 48 89 eb 0f 85 2c 1c 00 00 45 8b 6d 00 <44> 89 f8 ff c0 48 8d 2c 85 00 20 c2 90 48 89 e8 48 c1 e8 03 0f b6 RSP: 0018:ffffc90000007578 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000080000100 RDX: 00000000000a5d62 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300 RBP: dffffc0000000000 R08: ffffffff8173fd65 R09: ffffffff8df41aa0 R10: dffffc0000000000 R11: ffffffff81acf3d0 R12: ffffffff8165d50c R13: 000000000001417d R14: ffffc90000007648 R15: 00000000000065d5 FS: 00007f5bf58206c0(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe8a40b7562 CR3: 000000007bd83000 CR4: 0000000000350ef0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x43c/0x720 mm/slub.c:5315 __alloc_skb+0x1dc/0x3a0 net/core/skbuff.c:679 __netdev_alloc_skb+0xc1/0x850 net/core/skbuff.c:754 netdev_alloc_skb include/linux/skbuff.h:3484 [inline] dev_alloc_skb include/linux/skbuff.h:3497 [inline] __ieee80211_beacon_get+0xc06/0x1880 net/mac80211/tx.c:5654 ieee80211_beacon_get_tim+0xb4/0x2b0 net/mac80211/tx.c:5776 ieee80211_beacon_get include/net/mac80211.h:5669 [inline] mac80211_hwsim_beacon_tx+0x3c5/0x870 drivers/net/wireless/virtual/mac80211_hwsim.c:2361 __iterate_interfaces+0x2ab/0x590 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797 mac80211_hwsim_beacon+0xbb/0x180 drivers/net/wireless/virtual/mac80211_hwsim.c:2395 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1858 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x20/0x3b0 kernel/locking/lockdep.c:5876 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 20 f1 e1 10 <48> 89 44 24 28 0f 1f 44 00 00 65 8b 05 23 f1 e1 10 83 f8 08 0f 83 RSP: 0018:ffffc90004c378b8 EFLAGS: 00000286 RAX: 495308a71e507700 RBX: 00007f5bf581ff00 RCX: 0000000000000046 RDX: 000000009c930800 RSI: ffffffff820e81b0 RDI: ffff888076db3440 RBP: ffffc90004c37af0 R08: ffffffff820e81b0 R09: ffff888076db3440 R10: dffffc0000000000 R11: ffffed1006bc37a1 R12: 00007f5bf581fd00 R13: ffffffff820e81b0 R14: ffff888076db3440 R15: ffff888035e1bd00 __clear_user arch/x86/include/asm/uaccess_64.h:181 [inline] copy_fpstate_to_sigframe+0x13a/0xcc0 arch/x86/kernel/fpu/signal.c:203 get_sigframe+0x58d/0x7d0 arch/x86/kernel/signal.c:163 x64_setup_rt_frame+0x15b/0xd40 arch/x86/kernel/signal_64.c:175 setup_rt_frame arch/x86/kernel/signal.c:250 [inline] handle_signal arch/x86/kernel/signal.c:294 [inline] arch_do_signal_or_restart+0x3d1/0x7a0 arch/x86/kernel/signal.c:339 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5bf498f747 Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 RSP: 002b:00007f5bf58200e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f5bf4be5fa8 RCX: 00007f5bf498f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f5bf4be5fa8 RBP: 00007f5bf4be5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5bf4be6038 R14: 00007ffd2af9f3d0 R15: 00007ffd2af9f4b8