[FFmpeg-cvslog] avcodec/rka: avoid undefined multiply in cmode==0

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue May  2 01:09:58 2023 +0200| [b168aeb734069b09ab174666169f9c5dd631fb1b] | committer: Michael Niedermayer

avcodec/rka: avoid undefined multiply in  cmode==0

Fixes: signed integer overflow: -182838 * 32768 cannot be represented in type 'int'
Fixes: 58179/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RKA_fuzzer-5333265899978752

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=b168aeb734069b09ab174666169f9c5dd631fb1b
---

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

diff --git a/libavcodec/rka.c b/libavcodec/rka.c
index ce39a902af..e0ed8c16e4 100644
--- a/libavcodec/rka.c
+++ b/libavcodec/rka.c
@@ -732,7 +732,7 @@ static int decode_filter(RKAContext *s, ChContext *ctx, ACoder *ac, int off, uns
                 if (bits == 0) {
                     ctx->buf1[off] = sum + val;
                 } else {
-                    ctx->buf1[off] = (val + (sum >> bits)) * (1 << bits) +
+                    ctx->buf1[off] = (val + (sum >> bits)) * (1U << bits) +
                         (((1U << bits) - 1U) & ctx->buf1[off + -1]);
                 }
                 ctx->buf0[off] = ctx->buf1[off] + ctx->buf0[off + -1];