rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4987/1:b..l P5281/1:b..l rcu: (detected by 0, t=10503 jiffies, g=35897, q=173 ncpus=2) task:dhcpcd state:R running task stack:25752 pid:5281 tgid:5281 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:23 [inline] RIP: 0010:lock_acquire+0x58/0x350 kernel/locking/lockdep.c:5831 Code: 8b 05 bc 7f 98 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 bf 7f 98 11 83 f8 08 0f 83 83 01 00 00 89 c0 48 0f a3 05 68 57 8f 0e <73> 0d e8 51 29 09 00 84 c0 0f 84 ca 01 00 00 83 3d 62 8a 8f 0e 00 RSP: 0018:ffffc90003667500 EFLAGS: 00000297 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e959a20 RBP: ffffffff8176a21f R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90003667698 R11: ffffffff81b10630 R12: 0000000000000002 R13: ffffffff8e959a20 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5672 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x312/0x750 mm/slub.c:5347 _kmalloc_noprof include/linux/slab.h:973 [inline] _kzalloc_noprof include/linux/slab.h:1286 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x2ad/0x570 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x5fa/0x640 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x246/0x5f0 security/tomoyo/file.c:728 security_file_ioctl+0xc3/0x2a0 security/security.c:2512 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl+0x47/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4dda277378 RSP: 002b:00007ffff1560d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000557826a80dc0 RCX: 00007f4dda277378 RDX: 00007ffff1560d90 RSI: 0000000000008921 RDI: 000000000000000f RBP: 00007ffff1560d90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000557826a63700 R13: 0000557826a80dc0 R14: 0000557826a63700 R15: 00007ffff1560fe0 task:udevd state:R running task stack:23152 pid:4987 tgid:4987 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7552 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0xb26/0x2550 arch/x86/kernel/unwind_orc.c:-1 Code: 84 c0 0f 85 3b 14 00 00 0f b6 72 01 83 e6 07 83 fe 04 0f 84 39 04 00 00 83 fe 03 0f 84 f1 01 00 00 83 fe 02 0f 85 a2 07 00 00 <48> 89 5c 24 48 49 8d 7e 08 48 89 fb 48 c1 eb 03 42 80 3c 23 00 74 RSP: 0018:ffffc900025d7360 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff90d3b9a7 RCX: ffffffff905360c4 RDX: ffffffff90d3b9a6 RSI: 0000000000000002 RDI: ffffffff8c2910c0 RBP: 1ffffffff21a7734 R08: ffffc900025d7830 R09: 0000000000000000 R10: ffffc900025d7458 R11: ffffffff81b10630 R12: dffffc0000000000 R13: ffffffff90d3b9a2 R14: ffffc900025d7408 R15: 1ffff920004bae81 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 __slab_free+0x274/0x2c0 mm/slub.c:5672 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4610 [inline] slab_alloc_node mm/slub.c:4939 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0x312/0x750 mm/slub.c:5347 _kmalloc_noprof include/linux/slab.h:973 [inline] tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827 security_inode_getattr+0x12b/0x310 security/security.c:1895 vfs_getattr+0x23/0x70 fs/stat.c:259 vfs_statx_path+0x2b/0x230 fs/stat.c:299 vfs_statx+0x12e/0x200 fs/stat.c:356 vfs_fstatat+0x11b/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f63aad11b0a RSP: 002b:00007fff09ccdff8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000556399065fa0 RCX: 00007f63aad11b0a RDX: 00007fff09cce000 RSI: 0000556399065fa0 RDI: 00000000ffffff9c RBP: 0000556399054bf0 R08: 00063478c1c69200 R09: 3fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff09cce000 R13: 00005563762bc100 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 9608 jiffies! g35897 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3226 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:unwind_next_frame+0x19d8/0x2550 arch/x86/kernel/unwind_orc.c:693 Code: 49 8d 56 40 4c 89 f7 4c 89 c6 e8 33 0e 00 00 84 c0 0f 84 4e 01 00 00 48 bb 00 00 00 00 00 fc ff df 48 8b 44 24 10 0f b6 04 18 <84> c0 0f 85 7b 08 00 00 40 b5 01 8b 44 24 5c 41 39 06 4c 8b 6c 24 RSP: 0018:ffffc90000a07b00 EFLAGS: 00000202 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000001 RDX: ffffc90000a07be8 RSI: dffffc0000000000 RDI: ffffc90000a07fb0 RBP: 1ffffffff21a5b26 R08: ffffc90000a07fb0 R09: 0000000000000000 R10: ffffc90000a07bf8 R11: fffff52000140f81 R12: dffffc0000000000 R13: ffffffff90d2d92f R14: ffffc90000a07ba8 R15: ffffc90000a07bf0 FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f31851ec4b8 CR3: 000000007faf6000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6310 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6437 kfree_skb_reason include/linux/skbuff.h:1325 [inline] kfree_skb include/linux/skbuff.h:1334 [inline] ip6_mc_input+0x909/0xbc0 net/ipv6/ip6_input.c:638 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:988 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] netif_receive_skb_internal net/core/dev.c:6405 [inline] netif_receive_skb+0x278/0xbf0 net/core/dev.c:6464 NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:318 br_handle_frame_finish+0x1192/0x1990 net/bridge/br_input.c:-1 br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442 __netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6093 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x706/0x1860 net/core/dev.c:6670 __napi_poll+0xaa/0x330 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7949 handle_softirqs+0x225/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] __batadv_dat_purge net/batman-adv/distributed-arp-table.c:186 [inline] batadv_dat_purge+0x2d7/0x3c0 net/batman-adv/distributed-arp-table.c:205 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397 rescuer_thread+0x7b6/0x10b0 kernel/workqueue.c:3621 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 15618 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) net_ratelimit: 14637 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:d4:61:b1:62:fc, vlan:0)