[FFmpeg-cvslog] avformat/westwood_vqa: Check chunk size

[Michael Niedermayer]

ffmpeg | branch: release/4.2 | Michael Niedermayer <michael at niedermayer.cc> | Thu Sep 22 20:08:52 2022 +0200| [5f4b9be7e849e2671bdb2a8d9056682b0c661d70] | committer: Michael Niedermayer

avformat/westwood_vqa: Check chunk size

the type is also changed to int as it is interpreted as int in av_get_packet()

Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
Fixes: 50993/clusterfuzz-testcase-minimized-ffmpeg_dem_WSVQA_fuzzer-6593408795279360
Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_WSVQA_fuzzer-4613908817903616

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Anton Khirnov <anton at khirnov.net>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 5c0df3da0b7288a43a3b783117064cfcbc8037a5)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5f4b9be7e849e2671bdb2a8d9056682b0c661d70
---

 libavformat/westwood_vqa.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavformat/westwood_vqa.c b/libavformat/westwood_vqa.c
index c21a3e31f6..74275a3da5 100644
--- a/libavformat/westwood_vqa.c
+++ b/libavformat/westwood_vqa.c
@@ -163,13 +163,15 @@ static int wsvqa_read_packet(AVFormatContext *s,
     int ret = -1;
     uint8_t preamble[VQA_PREAMBLE_SIZE];
     uint32_t chunk_type;
-    uint32_t chunk_size;
-    int skip_byte;
+    int chunk_size;
+    unsigned skip_byte;
 
     while (avio_read(pb, preamble, VQA_PREAMBLE_SIZE) == VQA_PREAMBLE_SIZE) {
         chunk_type = AV_RB32(&preamble[0]);
         chunk_size = AV_RB32(&preamble[4]);
 
+        if (chunk_size < 0)
+            return AVERROR_INVALIDDATA;
         skip_byte = chunk_size & 0x01;
 
         if ((chunk_type == SND0_TAG) || (chunk_type == SND1_TAG) ||