avcodec/adpcm: Clip predictor for IMA_APM

Fixes: signed integer overflow: -2147483647 - 61436 cannot be represented in type 'int'
Fixes: 20492/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_IMA_APM_fuzzer-5092176004644864
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index c6735a49c9d6402743cb0ae1b11c0e0883babbd3..846ec5ef9c37c64b42dac5411eef3f98dbd249c5 100644 (file)
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -163,9 +163,9 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
         break;
     case AV_CODEC_ID_ADPCM_IMA_APM:
         if (avctx->extradata && avctx->extradata_size >= 16) {
-            c->status[0].predictor  = AV_RL32(avctx->extradata +  0);
+            c->status[0].predictor  = av_clip_intp2(AV_RL32(avctx->extradata +  0), 18);
             c->status[0].step_index = av_clip(AV_RL32(avctx->extradata +  4), 0, 88);
-            c->status[1].predictor  = AV_RL32(avctx->extradata +  8);
+            c->status[1].predictor  = av_clip_intp2(AV_RL32(avctx->extradata +  8), 18);
             c->status[1].step_index = av_clip(AV_RL32(avctx->extradata + 12), 0, 88);
         }
         break;