Commit 94c3187ef7 for ffmpeg

commit 94c3187ef7384735b2902abb34a95cbe2400a159
Author: Michael Niedermayer <michael@niedermayer.cc>
Date:   Tue Oct 6 23:17:58 2026 +0200

    avformat/mmst: Fail when the ASF header has no packet size or no streams

    The fix is the one recommended in the report.

    Fixes: NULL pointer dereference
    Fixes: 1eA5JUo2ED6K
    Fixes: AISLE-2026-0111-00154
    NULL pointer dereference Replicated through UnModified FFmpeg with ASAN,UBSAN
    Found-by: Joshua Rogers <joshua.rogers@aisle.com>

diff --git a/libavformat/mmst.c b/libavformat/mmst.c
index 59d3f9726e..78296a1f26 100644
--- a/libavformat/mmst.c
+++ b/libavformat/mmst.c
@@ -567,8 +567,10 @@ static int mms_open(URLContext *h, const char *uri, int flags)
     }
     mms->header_parsed = 1;

-    if (!mms->asf_packet_len || !mms->stream_num)
+    if (!mms->asf_packet_len || !mms->stream_num) {
+        err = AVERROR_INVALIDDATA;
         goto fail;
+    }

     clear_stream_buffers(mms);
     err = mms_safe_send_recv(mmst, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED);