[FFmpeg-devel] [PATCH 3/4] avcodec/bonk: Check unquant for overflow

[Michael Niedermayer]

Fixes: signed integer overflow: -2889074 * 2048 cannot be represented in type 'int'
Fixes: 51363/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-5660734784143360

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/bonk.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libavcodec/bonk.c b/libavcodec/bonk.c
index 471e09fe14..1695229dbd 100644
--- a/libavcodec/bonk.c
+++ b/libavcodec/bonk.c
@@ -363,12 +363,17 @@ static int bonk_decode(AVCodecContext *avctx, AVFrame *frame,
             return ret;
 
         for (int i = 0; i < samples_per_packet; i++) {
+            int64_t t64;
             for (int j = 0; j < s->down_sampling - 1; j++) {
                 sample[0] = predictor_calc_error(s->k, state, s->n_taps, 0);
                 sample++;
             }
 
-            sample[0] = predictor_calc_error(s->k, state, s->n_taps, s->input_samples[i] * quant);
+            t64 = s->input_samples[i] * (int64_t)quant;
+            if ((int32_t)t64 != t64)
+                return AVERROR_INVALIDDATA;
+
+            sample[0] = predictor_calc_error(s->k, state, s->n_taps, t64);
             sample++;
         }
 
-- 
2.17.1