syzbot

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BUG: KCSAN: data-race in kick_pool / wq_worker_running

read-write to 0xffff888237c299e4 of 4 bytes by task 13695 on cpu 0:
 wq_worker_running+0x95/0x120 kernel/workqueue.c:1400
 schedule_timeout+0xb7/0x170 kernel/time/sleep_timeout.c:99
 schedule_timeout_uninterruptible kernel/time/sleep_timeout.c:158 [inline]
 msleep+0x50/0x90 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 drivers/net/netdevsim/fib.c:889 [inline]
 nsim_fib_event_work+0x1ebc/0x21a0 drivers/net/netdevsim/fib.c:1493
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3319
 worker_thread+0x582/0x770 kernel/workqueue.c:3400
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c299e4 of 4 bytes by interrupt on cpu 1:
 need_more_worker kernel/workqueue.c:934 [inline]
 kick_pool+0x49/0x2d0 kernel/workqueue.c:1240
 __queue_work+0x8d6/0xb60 kernel/workqueue.c:2342
 queue_work_on+0xd1/0x160 kernel/workqueue.c:2392
 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:176 [inline]
 wg_packet_create_data drivers/net/wireguard/send.c:320 [inline]
 wg_packet_send_staged_packets+0x83d/0xab0 drivers/net/wireguard/send.c:388
 wg_packet_send_keepalive+0xeb/0x100 drivers/net/wireguard/send.c:239
 wg_expired_send_persistent_keepalive+0x3c/0x50 drivers/net/wireguard/timers.c:141
 call_timer_fn+0x38/0x2c0 kernel/time/timer.c:1789
 expire_timers kernel/time/timer.c:1840 [inline]
 __run_timers kernel/time/timer.c:2414 [inline]
 __run_timer_base+0x415/0x610 kernel/time/timer.c:2426
 run_timer_base kernel/time/timer.c:2435 [inline]
 run_timer_softirq+0x31/0x70 kernel/time/timer.c:2445
 handle_softirqs+0xb7/0x290 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x3a/0xc0 kernel/softirq.c:680
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
 pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:80
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x3d/0x70 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0xcb/0x240 kernel/sched/idle.c:325
 cpu_startup_entry+0x25/0x30 kernel/sched/idle.c:423
 start_secondary+0x95/0xa0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G        W           6.15.0-rc5-syzkaller-00353-gcd802e7e5f1e #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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