Avoid undefined shifts in calculateSbrEnvelope

Fixes: 26845/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LIBFDK_AAC_fuzzer-5670674796118016 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
mstorsjo · Nov 17, 2020 · 4b67304 · 4b67304
1 parent 52b6f5e
commit 4b67304
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/libSBRdec/src/env_calc.cpp b/libSBRdec/src/env_calc.cpp
@@ -1477,8 +1477,10 @@ void calculateSbrEnvelope(
 
       for (k = 0; k < noSubbands; k++) {
         int sc = scale_change - pNrgs->nrgGain_e[k] + (sc_change - 1);
-        pNrgs->nrgGain[k] >>= sc;
         pNrgs->nrgGain_e[k] += sc;
+        if (sc > 31)
+          sc = 31;
+        pNrgs->nrgGain[k] >>= sc;
       }
 
       if (!useLP) {