wireguard: fix potential leaks of async frame

The current implementation can cause memory leaks of async frames
and exhaust the async frames pool. Wireguard can early get async frame,
even when later it turns out it is not needed. Then such frame won't
be freed.

This fix changes the moment of acquiring async frame from the pool, so
it doesn't leak.

Type: fix
Signed-off-by: Gabriel Oginski <gabrielx.oginski@intel.com>
Change-Id: If7696de6a6f5db84e0dffef60caa31d4a5e6280e

1 files changed, 12 insertions, 12 deletions

diff --git a/src/plugins/wireguard/wireguard_output_tun.c b/src/plugins/wireguard/wireguard_output_tun.c
index c009d0ca57f..4d85a5912d6 100644
--- a/src/plugins/wireguard/wireguard_output_tun.c
+++ b/src/plugins/wireguard/wireguard_output_tun.c
@@ -246,7 +246,7 @@ error:
 
 static_always_inline enum noise_state_crypt
 wg_add_to_async_frame (vlib_main_t *vm, wg_per_thread_data_t *ptd,
-		       vnet_crypto_async_frame_t *async_frame,
+		       vnet_crypto_async_frame_t **async_frame,
 		       vlib_buffer_t *b, u8 *payload, u32 payload_len, u32 bi,
 		       u16 next, u16 async_next, noise_remote_t *r,
 		       uint32_t *r_idx, uint64_t *nonce, u8 *iv, f64 time)
@@ -284,8 +284,17 @@ wg_add_to_async_frame (vlib_main_t *vm, wg_per_thread_data_t *ptd,
   clib_memset (iv, 0, 4);
   clib_memcpy (iv + 4, nonce, sizeof (*nonce));
 
+  /* get a frame for this op if we don't yet have one or it's full  */
+  if (NULL == *async_frame || vnet_crypto_async_frame_is_full (*async_frame))
+    {
+      *async_frame = vnet_crypto_async_get_frame (
+	vm, VNET_CRYPTO_OP_CHACHA20_POLY1305_TAG16_AAD0_ENC);
+      /* Save the frame to the list we'll submit at the end */
+      vec_add1 (ptd->async_frames, *async_frame);
+    }
+
   /* this always succeeds because we know the frame is not full */
-  wg_output_tun_add_to_frame (vm, async_frame, kp->kp_send_index, payload_len,
+  wg_output_tun_add_to_frame (vm, *async_frame, kp->kp_send_index, payload_len,
 			      payload - b->data, bi, async_next, iv,
 			      payload + payload_len, flag);
 
@@ -479,17 +488,8 @@ wg_output_tun_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 
       if (is_async)
 	{
-	  /* get a frame for this op if we don't yet have one or it's full  */
-	  if (NULL == async_frame ||
-	      vnet_crypto_async_frame_is_full (async_frame))
-	    {
-	      async_frame = vnet_crypto_async_get_frame (
-		vm, VNET_CRYPTO_OP_CHACHA20_POLY1305_TAG16_AAD0_ENC);
-	      /* Save the frame to the list we'll submit at the end */
-	      vec_add1 (ptd->async_frames, async_frame);
-	    }
 	  state = wg_add_to_async_frame (
-	    vm, ptd, async_frame, b[0], plain_data, plain_data_len,
+	    vm, ptd, &async_frame, b[0], plain_data, plain_data_len,
 	    from[b - bufs], next[0], async_next_node, &peer->remote,
 	    &message_data_wg->receiver_index, &message_data_wg->counter,
 	    iv_data, time);