[FFmpeg-cvslog] avcodec/rka: avoid undefined doubling sum overflow

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Feb 20 20:09:36 2023 +0100| [a02e45a1f3cc6f07c7437c1e225dea2683f843cf] | committer: Michael Niedermayer

avcodec/rka: avoid undefined doubling sum overflow

Fixes: signed integer overflow: -2124073172 * 2 cannot be represented in type 'int'
Fixes: 56099/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RKA_fuzzer-4530933127839744

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a02e45a1f3cc6f07c7437c1e225dea2683f843cf
---

 libavcodec/rka.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/rka.c b/libavcodec/rka.c
index 1eb2289e58..2212e3f930 100644
--- a/libavcodec/rka.c
+++ b/libavcodec/rka.c
@@ -724,7 +724,7 @@ static int decode_filter(RKAContext *s, ChContext *ctx, ACoder *ac, int off, uns
             src = &ctx->buf1[off + -1];
             for (int i = 0; i < filt.size && i < 15; i++)
                 sum += filt.coeffs[i] * (unsigned)src[-i];
-            sum = sum * 2;
+            sum = sum * 2U;
             for (int i = 15; i < filt.size; i++)
                 sum += filt.coeffs[i] * (unsigned)src[-i];
             sum = sum >> 6;