[FFmpeg-cvslog] avcodec/wmavoice: Fix rounding and integer anomalies in calc_input_response()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sat Dec 14 15:27:44 2019 +0100| [e4c08e941907f0036e70ebcd7d9d15ec7e82c355] | committer: Michael Niedermayer

avcodec/wmavoice: Fix rounding and integer anomalies in calc_input_response()

Fixes: out of array access
Fixes: inf is outside the range of representable values of type 'int'
Fixes: signed integer overflow: -9223372036854775808 - 1 cannot be represented in type 'long'
Fixes: 19316/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMAVOICE_fuzzer-5677369365102592

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 38d37584448731f90977132b838d50ff1a28811b)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e4c08e941907f0036e70ebcd7d9d15ec7e82c355
---

 libavcodec/wmavoice.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavcodec/wmavoice.c b/libavcodec/wmavoice.c
index 799f719283..1ab93bb19c 100644
--- a/libavcodec/wmavoice.c
+++ b/libavcodec/wmavoice.c
@@ -607,12 +607,14 @@ static void calc_input_response(WMAVoiceContext *s, float *lpcs,
     for (n = 0; n <= 64; n++) {
         float pwr;
 
-        idx = FFMAX(0, lrint((max - lpcs[n]) * irange) - 1);
+        idx = lrint((max - lpcs[n]) * irange - 1);
+        idx = FFMAX(0, idx);
         pwr = wmavoice_denoise_power_table[s->denoise_strength][idx];
         lpcs[n] = angle_mul * pwr;
 
         /* 70.57 =~ 1/log10(1.0331663) */
-        idx = (pwr * gain_mul - 0.0295) * 70.570526123;
+        idx = av_clipf((pwr * gain_mul - 0.0295) * 70.570526123, 0, INT_MAX / 2);
+
         if (idx > 127) { // fall back if index falls outside table range
             coeffs[n] = wmavoice_energy_table[127] *
                         powf(1.0331663, idx - 127);