[FFmpeg-devel] [PATCH 1/3] avcodec/wavarc: Use unsigned for samples in 1dif, 2slp, 5elp

[Michael Niedermayer]

Fixes: signed integer overflow: 141394472 + 2038060365 cannot be represented in type 'int'
Fixes: 61787/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WAVARC_fuzzer-5882604925878272

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/wavarc.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/libavcodec/wavarc.c b/libavcodec/wavarc.c
index b954e8800cd..2e32b46ebd9 100644
--- a/libavcodec/wavarc.c
+++ b/libavcodec/wavarc.c
@@ -243,18 +243,18 @@ static int decode_1dif(AVCodecContext *avctx,
             break;
         case 3:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 4] = get_srice(gb, k) + (samples[n + 3] - samples[n + 2]) * 3 +
+                samples[n + 4] = get_srice(gb, k) + (samples[n + 3] - (unsigned)samples[n + 2]) * 3 +
                                           samples[n + 1];
             finished = 1;
             break;
         case 2:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 4] = get_srice(gb, k) + (samples[n + 3] * 2 - samples[n + 2]);
+                samples[n + 4] = get_srice(gb, k) + (samples[n + 3] * 2U - samples[n + 2]);
             finished = 1;
             break;
         case 1:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 4] = get_srice(gb, k) + samples[n + 3];
+                samples[n + 4] = get_srice(gb, k) + (unsigned)samples[n + 3];
             finished = 1;
             break;
         case 0:
@@ -343,13 +343,13 @@ static int decode_2slp(AVCodecContext *avctx,
             break;
         case 4:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] = get_srice(gb, k) + (samples[n + 69] - samples[n + 68]) * 3 +
+                samples[n + 70] = get_srice(gb, k) + (samples[n + 69] - (unsigned)samples[n + 68]) * 3 +
                                            samples[n + 67];
             finished = 1;
             break;
         case 3:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] = get_srice(gb, k) + (samples[n + 69] * 2 - samples[n + 68]);
+                samples[n + 70] = get_srice(gb, k) + (samples[n + 69] * 2U - samples[n + 68]);
             finished = 1;
             break;
         case 2:
@@ -359,7 +359,7 @@ static int decode_2slp(AVCodecContext *avctx,
             break;
         case 1:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] = get_srice(gb, k) + samples[n + 69];
+                samples[n + 70] = get_srice(gb, k) + (unsigned)samples[n + 69];
             finished = 1;
             break;
         case 0:
@@ -630,7 +630,7 @@ static int decode_5elp(AVCodecContext *avctx,
         case 20:
         case 7:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] += ac_out[n] + samples[n + 69] * 3 - samples[n + 68] * 3 + samples[n + 67];
+                samples[n + 70] += ac_out[n] + samples[n + 69] * 3U - samples[n + 68] * 3U + samples[n + 67];
             finished = 1;
             break;
         case 19:
@@ -653,14 +653,14 @@ static int decode_5elp(AVCodecContext *avctx,
                 samples[n] = ac_pred[n];
 
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] += ac_out[n] + samples[n + 69] * 3 - samples[n + 68] * 3 + samples[n + 67];
+                samples[n + 70] += ac_out[n] + samples[n + 69] * 3U - samples[n + 68] * 3U + samples[n + 67];
 
             finished = 1;
             break;
         case 18:
         case 5:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] += ac_out[n] + samples[n + 69] * 2 - samples[n + 68];
+                samples[n + 70] += ac_out[n] + samples[n + 69] * 2U - samples[n + 68];
             finished = 1;
             break;
         case 17:
@@ -672,7 +672,7 @@ static int decode_5elp(AVCodecContext *avctx,
         case 16:
         case 3:
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] += ac_out[n] + samples[n + 69];
+                samples[n + 70] += ac_out[n] + (unsigned)samples[n + 69];
             finished = 1;
             break;
         case 15:
@@ -695,7 +695,7 @@ static int decode_5elp(AVCodecContext *avctx,
                 samples[n] = ac_pred[n];
 
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] += samples[n + 69] * 2 - samples[n + 68];
+                samples[n + 70] += samples[n + 69] * 2U - samples[n + 68];
 
             finished = 1;
             break;
@@ -712,14 +712,14 @@ static int decode_5elp(AVCodecContext *avctx,
                 for (int o = 0; o < order; o++)
                     sum += s->filter[ch][o] * (unsigned)samples[n + 70 - o - 1];
 
-                samples[n + 70] += ac_out[n] + (sum >> 4);
+                samples[n + 70] += (unsigned)ac_out[n] + (sum >> 4);
             }
 
             for (int n = 0; n < 70; n++)
                 samples[n] = ac_pred[n];
 
             for (int n = 0; n < s->nb_samples; n++)
-                samples[n + 70] += samples[n + 69];
+                samples[n + 70] += (unsigned)samples[n + 69];
 
             finished = 1;
             break;
@@ -731,7 +731,7 @@ static int decode_5elp(AVCodecContext *avctx,
                 for (int o = 0; o < order; o++)
                     sum += s->filter[ch][o] * (unsigned)samples[n + 70 - o - 1];
 
-                samples[n + 70] += ac_out[n] + (sum >> 4);
+                samples[n + 70] += (unsigned)ac_out[n] + (sum >> 4);
             }
             finished = 1;
             break;
-- 
2.17.1