From: Nikita Zhandarovich n.zhandarovich@fintech.ru
[ Upstream commit bba045dc4d996d03dce6fe45726e78a1a1f6d4c3 ]
Syzkaller with KCSAN identified a data-race issue when accessing keypair->receiving_counter.counter. Use READ_ONCE() 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 ...
Fixes: a9e90d9931f3 ("wireguard: noise: separate receive counter from send counter") Reported-by: syzbot+d1de830e4ecdaac83d89@syzkaller.appspotmail.com Signed-off-by: Nikita Zhandarovich n.zhandarovich@fintech.ru Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Reviewed-by: Jiri Pirko jiri@nvidia.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireguard/receive.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index a176653c88616..db01ec03bda00 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -251,7 +251,7 @@ static bool decrypt_packet(struct sk_buff *skb, struct noise_keypair *keypair)
if (unlikely(!READ_ONCE(keypair->receiving.is_valid) || wg_birthdate_has_expired(keypair->receiving.birthdate, REJECT_AFTER_TIME) || - keypair->receiving_counter.counter >= REJECT_AFTER_MESSAGES)) { + READ_ONCE(keypair->receiving_counter.counter) >= REJECT_AFTER_MESSAGES)) { WRITE_ONCE(keypair->receiving.is_valid, false); return false; } @@ -318,7 +318,7 @@ static bool counter_validate(struct noise_replay_counter *counter, u64 their_cou for (i = 1; i <= top; ++i) counter->backtrack[(i + index_current) & ((COUNTER_BITS_TOTAL / BITS_PER_LONG) - 1)] = 0; - counter->counter = their_counter; + WRITE_ONCE(counter->counter, their_counter); }
index &= (COUNTER_BITS_TOTAL / BITS_PER_LONG) - 1; @@ -463,7 +463,7 @@ int wg_packet_rx_poll(struct napi_struct *napi, int budget) net_dbg_ratelimited("%s: Packet has invalid nonce %llu (max %llu)\n", peer->device->dev->name, PACKET_CB(skb)->nonce, - keypair->receiving_counter.counter); + READ_ONCE(keypair->receiving_counter.counter)); goto next; }