[FFmpeg-devel] [PATCH 4/5] avcodec/mobiclip: Check quantizer for overflow

Michael Niedermayer michael at niedermayer.cc
Sun Sep 11 01:30:45 EEST 2022


Fixes: signed integer overflow: 127 + 2147483536 cannot be represented in type 'int'
Fixes: 48798/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-6014034970804224

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/mobiclip.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c
index 5348f3bd6c3..aca462428c1 100644
--- a/libavcodec/mobiclip.c
+++ b/libavcodec/mobiclip.c
@@ -330,7 +330,7 @@ static av_cold int mobiclip_init(AVCodecContext *avctx)
     return 0;
 }
 
-static int setup_qtables(AVCodecContext *avctx, int quantizer)
+static int setup_qtables(AVCodecContext *avctx, int64_t quantizer)
 {
     MobiClipContext *s = avctx->priv_data;
     int qx, qy;
@@ -1256,7 +1256,7 @@ static int mobiclip_decode(AVCodecContext *avctx, AVFrame *rframe,
         frame->key_frame = 0;
         s->dct_tab_idx = 0;
 
-        ret = setup_qtables(avctx, s->quantizer + get_se_golomb(gb));
+        ret = setup_qtables(avctx, s->quantizer + (int64_t)get_se_golomb(gb));
         if (ret < 0)
             return ret;
 
-- 
2.17.1



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