[Spice-devel] [PATCH spice-server] gstreamer: Prevent integer overflow in delay computation

[Frediano Ziglio]

The partial expression "MSEC_PER_SEC * size * 8" can overflow if
size is 536870 or more. This as the operation is done using
32 bit unsigned integers. Being the size potentially double of
a compressed frame size the limit can be easily reached.
As get_average_frame_size already return a 64 bit use 64 bit
even for the size to avoid the integer overflow.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/gstreamer-encoder.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/server/gstreamer-encoder.c b/server/gstreamer-encoder.c
index e28ab00..988d193 100644
--- a/server/gstreamer-encoder.c
+++ b/server/gstreamer-encoder.c
@@ -511,7 +511,7 @@ static uint32_t get_min_playback_delay(SpiceGstEncoder *encoder)
      * an I frame) and an average frame. This also takes into account the
      * frames dropped by the encoder bit rate control.
      */
-    uint32_t size = get_maximum_frame_size(encoder) + get_average_frame_size(encoder);
+    uint64_t size = get_maximum_frame_size(encoder) + get_average_frame_size(encoder);
     uint32_t send_time = MSEC_PER_SEC * size * 8 / encoder->bit_rate;
 
     /* Also factor in the network latency with a margin for jitter. */
-- 
2.9.3