[FFmpeg-devel] RTSP Video Stream - Buffer Overflow!

[Yiğit (Yeet) Uyan]

Hi everyone,

RTSP/S links longer than 1024 characters are failing due to a buffer
overflow issue happening when parsing RTSP links (eg. ffplay <rtsp link>).
FFmpeg has a buffer definition in libavformat/Rtsp.h, where it defines the
control_uri as 1024 characters.

RTSP/S links follow a similar pattern to common web URIs, i.e.
<rtsps://my.camera.server:port/...>, and in many cases these links are
generated, routed and modified by common underlying web infrastructure. The
common conception for the web when parsing a URI is to expect up to 2000
characters.

https://stackoverflow.com/questions/417142/what-is-the-maximum-length-of-a-url-in-different-browsers

The link above is for browsers, but it is very similar in many other web
technologies as well.

Can somebody help with extending the rtsp/s link limit to match the web
urls (eg. 2048 characters)

Thanks in advance,


I have created and submitted the following patch to ffmpeg-devel at ffmpeg.org,
though it does not show up in patchwork. I am not sure what the following
steps are..

Signed-off-by: Yiğit (Yeet) Uyan <yigituyan at google.com>
---
 libavformat/rtsp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/rtsp.h b/libavformat/rtsp.h
index 54a9a30c16..2b37f5b49f 100644
--- a/libavformat/rtsp.h
+++ b/libavformat/rtsp.h
@@ -315,7 +315,7 @@ typedef struct RTSPState {
     /** some MS RTSP streams contain a URL in the SDP that we need to use
      * for all subsequent RTSP requests, rather than the input URI; in
      * other cases, this is a copy of AVFormatContext->filename. */
-    char control_uri[1024];
+    char control_uri[2048];