avcodec/ralf: Check num_blocks before use

Fixes: out of array access
Fixes: 20659/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RALF_fuzzer-5739471895265280

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 2020-05-11 22:17:43 +02:00
parent a035fd88ae
commit f0c0471075

View File

@ -482,6 +482,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
init_get_bits(&gb, src + 2, table_size);
ctx->num_blocks = 0;
while (get_bits_left(&gb) > 0) {
if (ctx->num_blocks >= FF_ARRAY_ELEMS(ctx->block_size))
return AVERROR_INVALIDDATA;
ctx->block_size[ctx->num_blocks] = get_bits(&gb, 13 + avctx->channels);
if (get_bits1(&gb)) {
ctx->block_pts[ctx->num_blocks] = get_bits(&gb, 9);