avcodec/sga: Check for array end in lzss_decompress()

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@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2021-03-17 22:19:33 +01:00
parent f44068db1e
commit e8bd34fe4f

View File

@ -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];