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BUG: KCSAN: data-race in kick_pool / wq_worker_running

read-write to 0xffff888237c2a8a4 of 4 bytes by task 21166 on cpu 0:
 wq_worker_running+0x9b/0x120 kernel/workqueue.c:1419
 schedule_timeout+0xca/0x180 kernel/time/sleep_timeout.c:99
 schedule_timeout_uninterruptible kernel/time/sleep_timeout.c:158 [inline]
 msleep+0x4f/0x90 kernel/time/sleep_timeout.c:318
 nsim_fib6_rt_add drivers/net/netdevsim/fib.c:693 [inline]
 nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:759 [inline]
 nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline]
 nsim_fib_event+0x491d/0x4d70 drivers/net/netdevsim/fib.c:889
 nsim_fib_event_work+0x13d/0x210 drivers/net/netdevsim/fib.c:1493
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359
 worker_thread+0x58a/0x780 kernel/workqueue.c:3440
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c2a8a4 of 4 bytes by interrupt on cpu 1:
 need_more_worker kernel/workqueue.c:937 [inline]
 kick_pool+0x49/0x2d0 kernel/workqueue.c:1259
 __queue_work+0x896/0xaf0 kernel/workqueue.c:2355
 queue_work_on+0xa9/0x140 kernel/workqueue.c:2405
 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:171 [inline]
 wg_packet_consume_data drivers/net/wireguard/receive.c:526 [inline]
 wg_packet_receive+0xdab/0x11a0 drivers/net/wireguard/receive.c:576
 wg_receive+0x4e/0x80 drivers/net/wireguard/socket.c:326
 udpv6_queue_rcv_one_skb+0xbfd/0xc80 net/ipv6/udp.c:863
 udpv6_queue_rcv_skb+0x213/0x2c0 net/ipv6/udp.c:924
 udp6_unicast_rcv_skb+0x1c9/0x1f0 net/ipv6/udp.c:1064
 __udp6_lib_rcv+0x999/0xb10 net/ipv6/udp.c:1153
 udpv6_rcv+0x4f/0x60 net/ipv6/udp.c:1267
 ip6_protocol_deliver_rcu+0xa89/0x10f0 net/ipv6/ip6_input.c:438
 ip6_input_finish+0xf0/0x1c0 net/ipv6/ip6_input.c:489
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ip6_input+0x5e/0x160 net/ipv6/ip6_input.c:500
 dst_input include/net/dst.h:480 [inline]
 ip6_rcv_finish+0x1f5/0x330 net/ipv6/ip6_input.c:79
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ipv6_rcv+0x72/0x170 net/ipv6/ip6_input.c:311
 __netif_receive_skb_one_core net/core/dev.c:6176 [inline]
 __netif_receive_skb net/core/dev.c:6289 [inline]
 process_backlog+0x2a5/0x670 net/core/dev.c:6640
 __napi_poll+0x61/0x330 net/core/dev.c:7704
 napi_poll net/core/dev.c:7767 [inline]
 net_rx_action+0x452/0x930 net/core/dev.c:7924
 handle_softirqs+0xb9/0x2a0 kernel/softirq.c:622
 do_softirq+0x45/0x60 kernel/softirq.c:523
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450
 __raw_read_unlock_bh include/linux/rwlock_api_smp.h:281 [inline]
 _raw_read_unlock_bh+0x1b/0x30 kernel/locking/spinlock.c:284
 wg_socket_send_skb_to_peer+0x111/0x130 drivers/net/wireguard/socket.c:184
 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
 wg_packet_tx_worker+0x12d/0x330 drivers/net/wireguard/send.c:276
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359
 worker_thread+0x58a/0x780 kernel/workqueue.c:3440
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 12016 Comm: kworker/1:14 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
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