rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3627/1:b..l (detected by 1, t=10502 jiffies, g=8849, q=39) task:kworker/u4:5 state:R running task stack:24856 pid: 3627 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 4c 7b 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900031378e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000626f28 RCX: 1ffff92000626ec8 RDX: dffffc0000000000 RSI: ffffffff8a8b3cc0 RDI: ffffffff8ad8f7c0 RBP: ffffc90003137a40 R08: dffffc0000000000 R09: fffffbfff1f8e219 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000626f24 R13: dffffc0000000000 R14: ffffc90003137940 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:755 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:826 [inline] batadv_iv_ogm_schedule+0x429/0x1000 net/batman-adv/bat_iv_ogm.c:869 batadv_iv_send_outstanding_bat_ogm_packet+0x6fa/0x800 net/batman-adv/bat_iv_ogm.c:1713 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 10527 jiffies! g8849 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:27064 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3238 Comm: dhcpcd Not tainted 5.15.165-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:rt6_select net/ipv6/route.c:912 [inline] RIP: 0010:fib6_table_lookup+0x820/0xbf0 net/ipv6/route.c:2189 Code: 4c 8b 74 24 30 74 08 48 89 df e8 4b 58 b8 f8 48 8b 3b 48 83 c7 18 e8 cf 12 2b 01 4c 8b 7c 24 10 48 8b 44 24 38 42 80 3c 28 00 <74> 08 4c 89 f7 e8 26 58 b8 f8 49 83 3e 00 74 0a e8 4b 8f 6e f8 e9 RSP: 0018:ffffc90000007320 EFLAGS: 00000246 RAX: 1ffff92000000ea7 RBX: 0000000000000000 RCX: ffff8880225f8000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007490 R08: ffffffff8911d028 R09: 000000000000002d R10: ffffc90000007420 R11: dffffc0000000001 R12: ffffc90000007530 R13: dffffc0000000000 R14: ffffc90000007538 R15: ffff88807a040a18 FS: 00007f3518135740(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f35182e1580 CR3: 0000000019f1a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip6_pol_route+0x1e7/0x15a0 net/ipv6/route.c:2225 pol_lookup_func include/net/ip6_fib.h:582 [inline] fib6_rule_lookup+0x265/0x620 net/ipv6/fib6_rules.c:115 ip6_route_input_lookup net/ipv6/route.c:2295 [inline] ip6_route_input+0x830/0xd90 net/ipv6/route.c:2591 ip6_rcv_finish+0x136/0x250 net/ipv6/ip6_input.c:77 NF_HOOK+0x364/0x410 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5485 [inline] __netif_receive_skb+0x1c6/0x530 net/core/dev.c:5599 process_backlog+0x363/0x7f0 net/core/dev.c:6476 __napi_poll+0xc7/0x440 net/core/dev.c:7035 napi_poll net/core/dev.c:7102 [inline] net_rx_action+0x617/0xda0 net/core/dev.c:7192 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558 do_softirq+0x162/0x240 kernel/softirq.c:459 __local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:383 sock_orphan include/net/sock.h:2025 [inline] unix_release_sock+0x270/0xaa0 net/unix/af_unix.c:531 unix_release+0x88/0xc0 net/unix/af_unix.c:940 __sock_release net/socket.c:649 [inline] sock_close+0xcd/0x230 net/socket.c:1336 __fput+0x3fe/0x8e0 fs/file_table.c:280 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f35182000a8 Code: 48 8b 05 83 9d 0d 00 64 c7 00 16 00 00 00 83 c8 ff 48 83 c4 20 5b c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 5b 48 8b 15 51 9d 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffe0a9fbfc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007f35182000a8 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000000000000000c RBP: 00007ffe0aa1c378 R08: 0000000000000007 R09: 69357b4db1fbcf78 R10: 0000000000004000 R11: 0000000000000246 R12: 000055c3b8f32870 R13: 00007ffe0aa0c1b8 R14: 0000000000000148 R15: 0000000000000004