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BUG: KCSAN: data-race in __mod_timer / timer_clear_idle

write to 0xffff88812c11cb24 of 1 bytes by task 0 on cpu 1:
 timer_clear_idle+0x2e/0x40 kernel/time/timer.c:1675
 tick_nohz_idle_retain_tick+0x3e/0x40 kernel/time/tick-sched.c:1004
 cpuidle_idle_call kernel/sched/idle.c:210 [inline]
 do_idle+0x287/0x310 kernel/sched/idle.c:276
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:372
 start_secondary+0xe3/0x110 arch/x86/kernel/smpboot.c:268
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

read to 0xffff88812c11cb24 of 1 bytes by interrupt on cpu 0:
 forward_timer_base kernel/time/timer.c:891 [inline]
 __mod_timer+0xb87/0xf00 kernel/time/timer.c:983
 mod_timer+0x1b/0x20 kernel/time/timer.c:1100
 mod_peer_timer drivers/net/wireguard/timers.c:37 [inline]
 wg_timers_any_authenticated_packet_traversal+0xc4/0xf0 drivers/net/wireguard/timers.c:215
 wg_packet_consume_data_done drivers/net/wireguard/receive.c:360 [inline]
 wg_packet_rx_poll+0x8c5/0x1370 drivers/net/wireguard/receive.c:482
 napi_poll+0x178/0x4a0 net/core/dev.c:6684
 net_rx_action+0x1ba/0x530 net/core/dev.c:6752
 __do_softirq+0x198/0x360 kernel/softirq.c:292
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 do_softirq_own_stack+0x5d/0x80 arch/x86/kernel/irq_64.c:77
 do_softirq+0x86/0xb0 kernel/softirq.c:337
 __local_bh_enable_ip+0x63/0x70 kernel/softirq.c:189
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
 _raw_spin_unlock_bh+0x33/0x40 kernel/locking/spinlock.c:207
 spin_unlock_bh include/linux/spinlock.h:398 [inline]
 ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
 wg_packet_decrypt_worker+0x6e7/0x720 drivers/net/wireguard/receive.c:507
 process_one_work+0x3e1/0x9a0 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x20d/0x230 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9242 Comm: kworker/0:4 Not tainted 5.8.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: wg-crypt-wg1 wg_packet_decrypt_worker
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