[FFmpeg-cvslog] libavcodec/8bps: Check that line lengths fit within the buffer

[Michael Niedermayer]

ffmpeg | branch: release/4.3 | Michael Niedermayer <michael at niedermayer.cc> | Mon Aug 22 22:10:09 2022 +0200| [4d1fd5c45408b2ad1e01ad953dcc8f64e6f3b45d] | committer: Michael Niedermayer

libavcodec/8bps: Check that line lengths fit within the buffer

Fixes: Timeout
Fixes: undefined pointer arithmetic
Fixes: 50330/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EIGHTBPS_fuzzer-5436287485607936

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 2316d5ec1a95b13ff9a0ce80409fa367a041966d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4d1fd5c45408b2ad1e01ad953dcc8f64e6f3b45d
---

 libavcodec/8bps.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/8bps.c b/libavcodec/8bps.c
index aa2318fa2d..655c62725b 100644
--- a/libavcodec/8bps.c
+++ b/libavcodec/8bps.c
@@ -70,6 +70,9 @@ static int decode_frame(AVCodecContext *avctx, void *data,
     unsigned char *planemap = c->planemap;
     int ret;
 
+    if (buf_size < planes * height *2)
+        return AVERROR_INVALIDDATA;
+
     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
         return ret;