rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-0): P5824/2:b..l P5720/1:b..l rcu: (detected by 0, t=12337 jiffies, g=32721, q=1938 ncpus=1) task:syz-executor state:R running task stack:20920 pid:5720 tgid:5720 ppid:5714 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 vprintk_emit+0x880/0xa40 kernel/printk/printk.c:2451 _printk+0xd5/0x120 kernel/printk/printk.c:2475 batadv_check_known_mac_addr+0x2bd/0x410 net/batman-adv/hard-interface.c:528 batadv_hard_if_event+0x3a8/0x17a0 net/batman-adv/hard-interface.c:992 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2218 [inline] call_netdevice_notifiers net/core/dev.c:2232 [inline] netif_set_mac_address+0x3db/0x510 net/core/dev.c:9605 do_setlink+0xa79/0x4370 net/core/rtnetlink.c:3103 rtnl_changelink net/core/rtnetlink.c:3769 [inline] __rtnl_newlink net/core/rtnetlink.c:3928 [inline] rtnl_newlink+0x17e2/0x1fe0 net/core/rtnetlink.c:4065 rtnetlink_rcv_msg+0x80f/0xd70 net/core/rtnetlink.c:6955 netlink_rcv_skb+0x208/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f8/0x9a0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8c3/0xcd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:727 __sys_sendto+0x365/0x4c0 net/socket.c:2180 __do_sys_sendto net/socket.c:2187 [inline] __se_sys_sendto net/socket.c:2183 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2183 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2ce978effc RSP: 002b:00007fffb1986f80 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f2cea4d4620 RCX: 00007f2ce978effc RDX: 000000000000002c RSI: 00007f2cea4d4670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fffb1986fd4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f2cea4d4670 R15: 0000000000000000 task:kworker/0:6 state:R running task stack:23080 pid:5824 tgid:5824 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: mld mld_dad_work Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:414 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline] __dev_queue_xmit+0x1780/0x3f60 net/core/dev.c:4660 dev_queue_xmit include/linux/netdevice.h:3350 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0x125c/0x1750 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x421/0x840 net/ipv6/ip6_output.c:226 NF_HOOK+0xa0/0x440 include/linux/netfilter.h:314 mld_sendpack+0x84a/0xdc0 net/ipv6/mcast.c:1868 mld_dad_work+0x44/0x500 net/ipv6/mcast.c:2308 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 9115 jiffies! g32721 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:26600 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 10 Comm: kworker/0:1 Not tainted 6.14.0-syzkaller-ga2cc6ff5ec8f #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: wg-crypt-wg1 wg_packet_encrypt_worker RIP: 0010:queue_work_on+0x26b/0x380 kernel/workqueue.c:2397 Code: 75 19 e8 18 4e 39 00 eb 18 e8 11 4e 39 00 e8 9c 18 a6 0a 48 83 7c 24 10 00 74 e7 e8 ff 4d 39 00 fb 48 c7 44 24 20 0e 36 e0 45 <4b> c7 04 37 00 00 00 00 43 c7 44 37 09 00 00 00 00 66 43 c7 44 37 RSP: 0018:ffffc900001c7460 EFLAGS: 00000293 RAX: ffffffff818a0981 RBX: 0000000000000000 RCX: ffff88801cef0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900001c7560 R08: ffffffff818a0951 R09: 1ffffffff20bf9ee R10: dffffc0000000000 R11: fffffbfff20bf9ef R12: 0000000000800001 R13: 0000000000000046 R14: 1ffff92000038e90 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88808c599000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4306b2bee0 CR3: 000000000eb38000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: wg_queue_enqueue_per_peer_tx+0x21f/0x4c0 drivers/net/wireguard/queueing.h:188 wg_packet_encrypt_worker+0x1430/0x1810 drivers/net/wireguard/send.c:305 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245