syzbot

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BUG: KCSAN: data-race in wg_packet_send_staged_packets / wg_packet_send_staged_packets

write to 0xffff888115e02b28 of 4 bytes by interrupt on cpu 1:
 wg_cpumask_next_online drivers/net/wireguard/queueing.h:130 [inline]
 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:173 [inline]
 wg_packet_create_data drivers/net/wireguard/send.c:320 [inline]
 wg_packet_send_staged_packets+0x6f9/0xae0 drivers/net/wireguard/send.c:388
 wg_packet_send_keepalive+0xe2/0x100 drivers/net/wireguard/send.c:239
 wg_expired_send_persistent_keepalive+0x3c/0x50 drivers/net/wireguard/timers.c:141
 call_timer_fn+0x3a/0x300 kernel/time/timer.c:1793
 expire_timers kernel/time/timer.c:1844 [inline]
 __run_timers kernel/time/timer.c:2418 [inline]
 __run_timer_base+0x417/0x640 kernel/time/timer.c:2429
 run_timer_base kernel/time/timer.c:2438 [inline]
 run_timer_softirq+0x31/0x70 kernel/time/timer.c:2448
 __do_softirq+0xc8/0x285 kernel/softirq.c:554
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu kernel/softirq.c:633 [inline]
 irq_exit_rcu+0x3c/0x90 kernel/softirq.c:645
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x73/0x80 arch/x86/kernel/apic/apic.c:1043
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x2f/0x50 kernel/locking/spinlock.c:202
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0xc8e/0x1080 kernel/signal.c:2914
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888115e02b28 of 4 bytes by interrupt on cpu 0:
 wg_cpumask_next_online drivers/net/wireguard/queueing.h:127 [inline]
 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:173 [inline]
 wg_packet_create_data drivers/net/wireguard/send.c:320 [inline]
 wg_packet_send_staged_packets+0x614/0xae0 drivers/net/wireguard/send.c:388
 wg_packet_send_keepalive+0xe2/0x100 drivers/net/wireguard/send.c:239
 wg_expired_send_persistent_keepalive+0x3c/0x50 drivers/net/wireguard/timers.c:141
 call_timer_fn+0x3a/0x300 kernel/time/timer.c:1793
 expire_timers kernel/time/timer.c:1844 [inline]
 __run_timers kernel/time/timer.c:2418 [inline]
 __run_timer_base+0x417/0x640 kernel/time/timer.c:2429
 run_timer_base kernel/time/timer.c:2438 [inline]
 run_timer_softirq+0x31/0x70 kernel/time/timer.c:2448
 __do_softirq+0xc8/0x285 kernel/softirq.c:554
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu kernel/softirq.c:633 [inline]
 irq_exit_rcu+0x3c/0x90 kernel/softirq.c:645
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x73/0x80 arch/x86/kernel/apic/apic.c:1043
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705
 instrument_copy_to_user include/linux/instrumented.h:113 [inline]
 _copy_to_user+0x66/0xa0 lib/usercopy.c:40
 copy_to_user include/linux/uaccess.h:191 [inline]
 copy_siginfo_to_user+0x24/0x90 kernel/signal.c:3380
 x64_setup_rt_frame+0x29a/0x570 arch/x86/kernel/signal_64.c:194
 setup_rt_frame arch/x86/kernel/signal.c:223 [inline]
 handle_signal arch/x86/kernel/signal.c:267 [inline]
 arch_do_signal_or_restart+0x287/0x4b0 arch/x86/kernel/signal.c:312
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7283 Comm: syz-executor.3 Tainted: G        W          6.9.0-rc6-syzkaller-00290-gb9158815de52 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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