[FFmpeg-devel] [PATCH 1/3] avcodec/ffv1dec: Check that num h/v slices is supported

[Michael Niedermayer]

Fixes: out of array access
Fixes: 55597/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFV1_fuzzer-4898293416329216

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/ffv1dec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index d74786cec3..180d24e695 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -475,6 +475,11 @@ static int read_extra_header(FFV1Context *f)
         return AVERROR_INVALIDDATA;
     }
 
+    if (f->num_h_slices > MAX_SLICES / f->num_v_slices) {
+        av_log(f->avctx, AV_LOG_ERROR, "slice count unsupported\n");
+        return AVERROR_PATCHWELCOME;
+    }
+
     f->quant_table_count = get_symbol(c, state, 0);
     if (f->quant_table_count > (unsigned)MAX_QUANT_TABLES || !f->quant_table_count) {
         av_log(f->avctx, AV_LOG_ERROR, "quant table count %d is invalid\n", f->quant_table_count);
-- 
2.17.1