==================================================================
BUG: KCSAN: data-race in wg_packet_send_staged_packets / wg_packet_send_staged_packets

write to 0xffff88801c240a08 of 4 bytes by interrupt on cpu 1:
 wg_cpumask_next_online drivers/net/wireguard/queueing.h:134 [inline]
 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:153 [inline]
 wg_packet_create_data drivers/net/wireguard/send.c:326 [inline]
 wg_packet_send_staged_packets+0x5d5/0x990 drivers/net/wireguard/send.c:396
 wg_packet_send_keepalive+0xea/0x100 drivers/net/wireguard/send.c:239
 wg_expired_send_persistent_keepalive+0x38/0x50 drivers/net/wireguard/timers.c:141
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1417
 expire_timers+0x116/0x260 kernel/time/timer.c:1462
 __run_timers+0x338/0x3d0 kernel/time/timer.c:1731
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1744
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu+0xb4/0xc0 kernel/softirq.c:420
 sysvec_apic_timer_interrupt+0x74/0x90 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:516 [inline]
 acpi_idle_enter+0x25b/0x2e0 drivers/acpi/processor_idle.c:647
 cpuidle_enter_state+0x2bd/0x750 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x193/0x230 kernel/sched/idle.c:299
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:396
 secondary_startup_64_no_verify+0xb0/0xbb

read to 0xffff88801c240a08 of 4 bytes by interrupt on cpu 0:
 wg_cpumask_next_online drivers/net/wireguard/queueing.h:130 [inline]
 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:153 [inline]
 wg_packet_create_data drivers/net/wireguard/send.c:326 [inline]
 wg_packet_send_staged_packets+0x592/0x990 drivers/net/wireguard/send.c:396
 wg_packet_send_keepalive+0xea/0x100 drivers/net/wireguard/send.c:239
 wg_expired_send_persistent_keepalive+0x38/0x50 drivers/net/wireguard/timers.c:141
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1417
 expire_timers+0x116/0x260 kernel/time/timer.c:1462
 __run_timers+0x338/0x3d0 kernel/time/timer.c:1731
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1744
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:343
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu+0xb4/0xc0 kernel/softirq.c:420
 sysvec_apic_timer_interrupt+0x74/0x90 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
 ipv4_mtu+0x23/0x200 net/ipv4/route.c:1317
 dst_mtu include/net/dst.h:198 [inline]
 tcp_current_mss+0x6d/0x110 net/ipv4/tcp_output.c:1835
 tcp_sacktag_write_queue+0xbc7/0x1ab0 net/ipv4/tcp_input.c:1857
 tcp_ack+0xcc9/0x3450 net/ipv4/tcp_input.c:3774
 tcp_rcv_established+0x4b7/0x1450 net/ipv4/tcp_input.c:5877
 tcp_v4_do_rcv+0x278/0x4a0 net/ipv4/tcp_ipv4.c:1676
 sk_backlog_rcv include/net/sock.h:1016 [inline]
 __release_sock+0xf5/0x270 net/core/sock.c:2542
 release_sock+0x40/0x110 net/core/sock.c:3066
 sk_stream_wait_memory+0x449/0x730 net/core/stream.c:145
 tcp_sendmsg_locked+0xc59/0x2130 net/ipv4/tcp.c:1419
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1459
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:817
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0x2a8/0x370 net/socket.c:1975
 __do_sys_sendto net/socket.c:1987 [inline]
 __se_sys_sendto net/socket.c:1983 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:1983
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31579 Comm: syz-executor.2 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================