[FFmpeg-cvslog] avcodec/ffv1dec: Check that num h/v slices is supported

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sat Feb 18 22:33:02 2023 +0100| [8094b114119f1b8bad43a1a1596645111e6fb2c3] | committer: Michael Niedermayer

avcodec/ffv1dec: Check that num h/v slices is supported

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>
(cherry picked from commit 8ead0ae68eb64ad325efafd686c434727f3d666a)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8094b114119f1b8bad43a1a1596645111e6fb2c3
---

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

diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index 0888c3c2a7..c0c1549a2f 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -579,6 +579,11 @@ 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);