[FFmpeg-devel] [PATCH 2/3] avcodec/sga: Check for array end in lzss_decompress()

[Michael Niedermayer]

Fixes: out of array access
Fixes: 31640/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SGA_fuzzer-5630883286614016
Fixes: 31619/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SGA_fuzzer-5176667708456960

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/sga.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/sga.c b/libavcodec/sga.c
index 00752a5843..881f3fa6b2 100644
--- a/libavcodec/sga.c
+++ b/libavcodec/sga.c
@@ -232,7 +232,7 @@ static int lzss_decompress(AVCodecContext *avctx,
 
                 if (offset <= 0)
                     offset = 1;
-                if (oi < offset)
+                if (oi < offset || oi + count * 2 > dst_size )
                     return AVERROR_INVALIDDATA;
                 for (int j = 0; j < count * 2; j++) {
                     dst[oi] = dst[oi - offset];
-- 
2.17.1