[FFmpeg-devel] [PATCH 4/4] avcodec/adpcm: XA: Check shift similar to filter

[Michael Niedermayer]

Fixes: negative shift
Fixes: 22499/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_XA_fuzzer-5765452130418688

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/adpcm.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index dc4a9222af..79c5d625d1 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -559,6 +559,10 @@ static int xa_decode(AVCodecContext *avctx, int16_t *out0, int16_t *out1,
             avpriv_request_sample(avctx, "unknown XA-ADPCM filter %d", filter);
             filter=0;
         }
+        if (shift < 0) {
+            avpriv_request_sample(avctx, "unknown XA-ADPCM shift %d", shift);
+            shift = 0;
+        }
         f0 = xa_adpcm_table[filter][0];
         f1 = xa_adpcm_table[filter][1];
 
@@ -584,10 +588,14 @@ static int xa_decode(AVCodecContext *avctx, int16_t *out0, int16_t *out1,
 
         shift  = 12 - (in[5+i*2] & 15);
         filter = in[5+i*2] >> 4;
-        if (filter >= FF_ARRAY_ELEMS(xa_adpcm_table)) {
+        if (filter >= FF_ARRAY_ELEMS(xa_adpcm_table) || shift < 0) {
             avpriv_request_sample(avctx, "unknown XA-ADPCM filter %d", filter);
             filter=0;
         }
+        if (shift < 0) {
+            avpriv_request_sample(avctx, "unknown XA-ADPCM shift %d", shift);
+            shift = 0;
+        }
 
         f0 = xa_adpcm_table[filter][0];
         f1 = xa_adpcm_table[filter][1];
-- 
2.17.1