From: "Jason A. Donenfeld" Jason@zx2c4.com
stable inclusion from stable-v5.10.84 commit cb2d7c1992cb7019499831abf0f32759905bc248 bugzilla: 186030 https://gitee.com/openeuler/kernel/issues/I4QV2F
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit fb32f4f606c17b869805d7cede8b03d78339b50a upstream.
If we're being delivered packets from multiple CPUs so quickly that the ring lock is contended for CPU tries, then it's safe to assume that the queue is near capacity anyway, so just drop the packet rather than spinning. This helps deal with multicore DoS that can interfere with data path performance. It _still_ does not completely fix the issue, but it again chips away at it.
Reported-by: Streun Fabio fstreun@student.ethz.ch Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/net/wireguard/receive.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index f4e537e3e8ec..7b8df406c773 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -554,9 +554,19 @@ void wg_packet_receive(struct wg_device *wg, struct sk_buff *skb) case cpu_to_le32(MESSAGE_HANDSHAKE_INITIATION): case cpu_to_le32(MESSAGE_HANDSHAKE_RESPONSE): case cpu_to_le32(MESSAGE_HANDSHAKE_COOKIE): { - int cpu; - if (unlikely(!rng_is_initialized() || - ptr_ring_produce_bh(&wg->handshake_queue.ring, skb))) { + int cpu, ret = -EBUSY; + + if (unlikely(!rng_is_initialized())) + goto drop; + if (atomic_read(&wg->handshake_queue_len) > MAX_QUEUED_INCOMING_HANDSHAKES / 2) { + if (spin_trylock_bh(&wg->handshake_queue.ring.producer_lock)) { + ret = __ptr_ring_produce(&wg->handshake_queue.ring, skb); + spin_unlock_bh(&wg->handshake_queue.ring.producer_lock); + } + } else + ret = ptr_ring_produce_bh(&wg->handshake_queue.ring, skb); + if (ret) { + drop: net_dbg_skb_ratelimited("%s: Dropping handshake packet from %pISpfsc\n", wg->dev->name, skb); goto err;