rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5710/1:b..l P5258/1:b..l P11089/1:b..l P6230/1:b..l P4963/1:b..l rcu: (detected by 0, t=10502 jiffies, g=58005, q=4581 ncpus=1) task:udevd state:R running task stack:23480 pid:4963 tgid:4963 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5893 Code: ff 65 0f c1 05 a3 7b 7d 12 83 f8 01 0f 85 27 01 00 00 9c 58 f6 c4 02 0f 85 12 01 00 00 41 f7 c6 00 02 00 00 0f 85 c8 00 00 00 <48> 8b 44 24 10 65 48 2b 05 ad 34 7d 12 0f 85 4d 01 00 00 48 83 c4 RSP: 0018:ffffc90003b3faa0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8ebe8200 RCX: ffffc90003b3faac RDX: 0000000000000001 RSI: ffffffff8e1835cb RDI: ffffffff8c400480 RBP: ffffffff828599cd R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88807dec0000 R13: 0000000005f801cf R14: 0000000000000202 R15: 0000000000000002 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] __update_page_owner_free_handle.isra.0+0x302/0x4b0 mm/page_owner.c:295 __reset_page_owner+0x93/0x190 mm/page_owner.c:321 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931 alloc_filename fs/namei.c:147 [inline] do_getname+0x35/0x390 fs/namei.c:187 getname include/linux/fs.h:2537 [inline] getname_maybe_null include/linux/fs.h:2544 [inline] class_filename_maybe_null_constructor include/linux/fs.h:2568 [inline] vfs_fstatat+0xd0/0xe0 fs/stat.c:368 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f036b711b0a RSP: 002b:00007ffd87d772d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055fde54de428 RCX: 00007f036b711b0a RDX: 00007ffd87d772e0 RSI: 000055fde54cced3 RDI: 00000000ffffff9c RBP: 000055fdf8ceb668 R08: 00063478c1c69200 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd87d772e0 R14: 0000000000000000 R15: 00063478c1c69200 task:kworker/u8:11 state:R running task stack:25912 pid:6230 tgid:6230 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: krds_cp_wq#0/0 rds_connect_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_notrace+0x5f/0xd0 kernel/sched/core.c:7506 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:753 trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x301/0x370 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] __page_table_check_zero+0x8b/0x410 mm/page_table_check.c:138 page_table_check_free include/linux/page_table_check.h:46 [inline] __free_pages_prepare mm/page_alloc.c:1407 [inline] __free_frozen_pages+0x790/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931 sk_prot_alloc+0x60/0x2a0 net/core/sock.c:2245 sk_alloc+0x36/0xe80 net/core/sock.c:2307 inet_create net/ipv4/af_inet.c:333 [inline] inet_create+0x3a0/0x1060 net/ipv4/af_inet.c:259 __sock_create+0x339/0x860 net/socket.c:1651 rds_tcp_conn_path_connect+0x304/0xaa0 net/rds/tcp_connect.c:125 rds_connect_worker+0x1b4/0x2d0 net/rds/threads.c:176 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:modprobe state:R running task stack:25176 pid:11089 tgid:11089 ppid:138 task_flags:0x400100 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_notrace+0x5f/0xd0 kernel/sched/core.c:7506 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:753 trace_lock_release include/trace/events/lock.h:68 [inline] lock_release+0x24d/0x310 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931 vm_area_dup+0x27/0x8e0 mm/vma_init.c:123 __split_vma+0x18c/0xda0 mm/vma.c:516 split_vma mm/vma.c:599 [inline] vma_modify+0x12ad/0x25c0 mm/vma.c:1699 vma_modify_flags+0x257/0x3d0 mm/vma.c:1719 mprotect_fixup+0x27a/0xe30 mm/mprotect.c:789 do_mprotect_pkey+0xa4b/0xef0 mm/mprotect.c:967 __do_sys_mprotect mm/mprotect.c:988 [inline] __se_sys_mprotect mm/mprotect.c:985 [inline] __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:985 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe0bd39a2c7 RSP: 002b:00007ffc1248b0a8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 00007fe0bd3ae310 RCX: 00007fe0bd39a2c7 RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000564ede164000 RBP: 00007ffc1248b370 R08: 0000000000000000 R09: 00007fe0bd2be04a R10: 00007fe0bd3ae310 R11: 0000000000000206 R12: 0000000000000000 R13: 00000132173f9a5f R14: 0000000000000000 R15: 00007fe0bd3ae310 task:dhcpcd state:R running task stack:25800 pid:5258 tgid:5258 ppid:1 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:198 sock_def_readable+0x154/0x600 net/core/sock.c:3658 unix_dgram_sendmsg+0xc8f/0x1810 net/unix/af_unix.c:2293 unix_seqpacket_sendmsg+0x12a/0x1d0 net/unix/af_unix.c:2538 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] sock_write_iter+0x53a/0x5b0 net/socket.c:1241 do_iter_readv_writev+0x6f7/0x930 fs/read_write.c:828 vfs_writev+0x360/0xdd0 fs/read_write.c:1058 do_writev+0x28a/0x340 fs/read_write.c:1104 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f869c90c407 RSP: 002b:00007ffff1ea6590 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f869c882780 RCX: 00007f869c90c407 RDX: 0000000000000005 RSI: 00007ffff1ea65f0 RDI: 000000000000000a RBP: 0000560c1852d1e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000560c1852d1e0 R13: 000000000000012c R14: 00000000ffffffff R15: 0000000000000000 task:kworker/0:6 state:R running task stack:21408 pid:5710 tgid:5710 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:457 local_bh_enable include/linux/bottom_half.h:33 [inline] nf_ct_delete_from_lists net/netfilter/nf_conntrack_core.c:647 [inline] nf_ct_delete+0x261/0x650 net/netfilter/nf_conntrack_core.c:697 nf_ct_kill include/net/netfilter/nf_conntrack.h:231 [inline] nf_ct_gc_expired.part.0+0x17e/0x200 net/netfilter/nf_conntrack_core.c:742 nf_ct_gc_expired net/netfilter/nf_conntrack_core.c:735 [inline] gc_worker+0xc1f/0x1a10 net/netfilter/nf_conntrack_core.c:1562 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 1244 jiffies! g58005 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:28984 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: CPU: 0 UID: 0 PID: 3214 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:rps_input_queue_tail_save include/net/rps.h:181 [inline] RIP: 0010:enqueue_to_backlog+0x35d/0x1130 net/core/dev.c:5420 Code: f8 48 85 db 0f 85 12 04 00 00 e8 be 9a 7e f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 4c 95 7e f8 48 85 db 0f 85 9b 0a 00 00 9e 9a 7e f8 48 8b 4c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffffc90000006e40 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff898bdceb RDX: ffff88803428a540 RSI: ffffffff898bdcf9 RDI: ffff88803428a540 RBP: 00000000002895ea R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881caecb8c0 R13: ffff8880b843d2a0 R14: ffff8880b843d2b0 R15: ffffffff94651080 FS: 0000000000000000(0000) GS:ffff888123dec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555649554e8 CR3: 000000005bb6f000 CR4: 00000000003526f0 Call Trace: netif_rx_internal+0x102/0x600 net/core/dev.c:5729 __netif_rx+0x88/0xb0 net/core/dev.c:5749 loopback_xmit+0x284/0x6e0 drivers/net/loopback.c:90 __netdev_start_xmit include/linux/netdevice.h:5397 [inline] netdev_start_xmit include/linux/netdevice.h:5406 [inline] xmit_one net/core/dev.c:3889 [inline] dev_hard_start_xmit+0x121/0x760 net/core/dev.c:3905 __dev_queue_xmit+0x1bbf/0x4970 net/core/dev.c:4878 dev_queue_xmit include/linux/netdevice.h:3448 [inline] neigh_hh_output include/net/neighbour.h:544 [inline] neigh_output include/net/neighbour.h:558 [inline] ip_finish_output2+0xf4a/0x2400 net/ipv4/ip_output.c:236 __ip_finish_output.part.0+0x444/0x6f0 net/ipv4/ip_output.c:314 __ip_finish_output net/ipv4/ip_output.c:302 [inline] ip_finish_output net/ipv4/ip_output.c:324 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x39b/0xc10 net/ipv4/ip_output.c:437 dst_output include/net/dst.h:470 [inline] ip_local_out+0x193/0x1f0 net/ipv4/ip_output.c:131 synproxy_send_tcp.isra.0+0x481/0x680 net/netfilter/nf_synproxy_core.c:442 synproxy_send_client_synack+0x6ea/0x970 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] nft_synproxy_do_eval+0xa1c/0xce0 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x2e5/0x19d0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ip_local_deliver+0x163/0x1f0 net/ipv4/ip_input.c:262 dst_input include/net/dst.h:480 [inline] ip_rcv_finish net/ipv4/ip_input.c:492 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_rcv+0x33a/0x3c0 net/ipv4/ip_input.c:612 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6212 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6325 process_backlog+0x37a/0x1580 net/core/dev.c:6676 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7735 napi_poll net/core/dev.c:7798 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7955 handle_softirqs+0x1ea/0x9b0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] __batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:186 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:167 [inline] batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:205 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3629 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245