CVE-2024-26861

In the Linux kernel, the following vulnerability has been resolved:

wireguard: receive: annotate data-race around receiving_counter.counter

Syzkaller with KCSAN identified a data-race issue when accessing keypair->receivingcounter.counter. Use READONCE() and WRITE_ONCE() annotations to mark the data race as intentional.

BUG: KCSAN: data-race in wg_packet_decrypt_worker / wg_packet_rx_poll

write to 0xffff888107765888 of 8 bytes by interrupt on cpu 0:
 counter_validate drivers/net/wireguard/receive.c:321 [inline]
 wg_packet_rx_poll+0x3ac/0xf00 drivers/net/wireguard/receive.c:461
 __napi_poll+0x60/0x3b0 net/core/dev.c:6536
 napi_poll net/core/dev.c:6605 [inline]
 net_rx_action+0x32b/0x750 net/core/dev.c:6738
 __do_softirq+0xc4/0x279 kernel/softirq.c:553
 do_softirq+0x5e/0x90 kernel/softirq.c:454
 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
 wg_packet_decrypt_worker+0x6c5/0x700 drivers/net/wireguard/receive.c:499
 process_one_work kernel/workqueue.c:2633 [inline]
 ...

read to 0xffff888107765888 of 8 bytes by task 3196 on cpu 1:
 decrypt_packet drivers/net/wireguard/receive.c:252 [inline]
 wg_packet_decrypt_worker+0x220/0x700 drivers/net/wireguard/receive.c:501
 process_one_work kernel/workqueue.c:2633 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2706
 worker_thread+0x525/0x730 kernel/workqueue.c:2787
 ...