rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P1664/1:b..l rcu: (detected by 1, t=10503 jiffies, g=127393, q=468495 ncpus=2) task:syz.4.13327 state:R running task stack:28392 pid:1664 tgid:1653 ppid:5850 task_flags:0x400040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67 Code: e8 f5 be af 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 07 c3 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 RSP: 0018:ffffc9001222f658 EFLAGS: 00000202 RAX: ffffc9001222fb01 RBX: ffffc90012228000 RCX: 0000000000000001 RDX: ffffc9001222f7c8 RSI: dffffc0000000000 RDI: ffffc9001222fb50 RBP: 1ffff92002445ef1 R08: ffffc9001222fb50 R09: 0000000000000000 R10: ffffc9001222f7d8 R11: fffff52002445efd R12: 1ffff92002445ef2 R13: 1ffff92002445ef3 R14: ffffc90012230000 R15: dffffc0000000000 deref_stack_reg+0x19f/0x230 arch/x86/kernel/unwind_orc.c:406 unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1 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:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2752 [inline] __put_partials+0x156/0x1a0 mm/slub.c:3217 put_cpu_partial+0x17c/0x250 mm/slub.c:3292 __slab_free+0x2d5/0x3c0 mm/slub.c:4549 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4179 [inline] slab_alloc_node mm/slub.c:4228 [inline] __do_kmalloc_node mm/slub.c:4363 [inline] __kmalloc_noprof+0x224/0x4f0 mm/slub.c:4376 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0xe7/0x220 net/core/sock.c:2239 sk_alloc+0x3a/0x370 net/core/sock.c:2295 __netlink_create+0x65/0x260 net/netlink/af_netlink.c:628 netlink_create+0x3ca/0x590 net/netlink/af_netlink.c:686 __sock_create+0x4b0/0x9f0 net/socket.c:1589 sock_create net/socket.c:1647 [inline] __sys_socket_create net/socket.c:1684 [inline] __sys_socket+0xd7/0x1b0 net/socket.c:1731 __do_sys_socket net/socket.c:1745 [inline] __se_sys_socket net/socket.c:1743 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f498d9908c7 RSP: 002b:00007f498e70dfa8 EFLAGS: 00000286 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f498dbb5fa0 RCX: 00007f498d9908c7 RDX: 0000000000000010 RSI: 0000000000000003 RDI: 0000000000000010 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000041c0 R11: 0000000000000286 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f498dbb5fa0 R15: 00007f498dcdfa28 rcu: rcu_preempt kthread starved for 469 jiffies! g127393 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 3407 Comm: kworker/R-bat_e Not tainted 6.16.0-syzkaller-08685-g260f6f4fda93 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:check_wait_context kernel/locking/lockdep.c:4870 [inline] RIP: 0010:__lock_acquire+0x467/0xd20 kernel/locking/lockdep.c:5187 Code: c5 45 8d 7c 24 01 49 ff cc 44 89 f9 83 c1 fe 78 44 44 89 e3 81 e3 ff ff ff 7f 83 f9 31 73 1d 48 8d 0c 9b 8b 8c cf 10 0b 00 00 <31> c1 41 ff cf 49 ff cc f7 c1 00 60 00 00 74 cf eb 1c 48 c7 c7 b0 RSP: 0018:ffffc90000006768 EFLAGS: 00000083 RAX: 0000000000022007 RBX: 0000000000000004 RCX: 0000000000022007 RDX: 0000000000000003 RSI: 0000000000002000 RDI: ffff88803020bc00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8172ad05 R10: ffffc900000069b8 R11: ffffffff81ac10b0 R12: 0000000000000004 R13: 0000000000000001 R14: ffff88803020c7b8 R15: 0000000000000006 FS: 0000000000000000(0000) GS:ffff888125c79000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb976e2c7c1 CR3: 0000000030946000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2416 [inline] slab_free mm/slub.c:4679 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4781 skb_release_all net/core/skbuff.c:1149 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] sk_skb_reason_drop+0xe9/0x170 net/core/skbuff.c:1203 kfree_skb_reason include/linux/skbuff.h:1275 [inline] kfree_skb include/linux/skbuff.h:1284 [inline] ip6_mc_input+0x8f4/0xaf0 net/ipv6/ip6_input.c:593 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:993 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc2/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:5979 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6092 netif_receive_skb_internal net/core/dev.c:6178 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6237 NF_HOOK+0xa0/0x390 include/linux/netfilter.h:319 br_handle_frame_finish+0x14d1/0x19b0 net/bridge/br_input.c:-1 br_nf_hook_thresh+0x3c3/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x948/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:434 __netif_receive_skb_core+0x10b9/0x4020 net/core/dev.c:5866 __netif_receive_skb_one_core net/core/dev.c:5977 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6092 process_backlog+0x60e/0x14f0 net/core/dev.c:6444 __napi_poll+0xc4/0x360 net/core/dev.c:7497 napi_poll net/core/dev.c:7560 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7687 handle_softirqs+0x286/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3509 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3498 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 net_ratelimit: 4714 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) net_ratelimit: 5395 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:d2:33:74:ac:1e:b3, vlan:0)