[FFmpeg-devel] [PATCH 3/6] avcodec/rka: Fix some integer anomalies
Michael Niedermayer
michael at niedermayer.cc
Mon Feb 20 21:29:26 EET 2023
Fixes: left shift of negative value -3201
Fixes: integer overflow: -76470276 * -25608 cannot be represented in type 'int'
Fixes: 56052/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RKA_fuzzer-5236218750435328
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/rka.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/libavcodec/rka.c b/libavcodec/rka.c
index 461baf1e1f..994c563ffd 100644
--- a/libavcodec/rka.c
+++ b/libavcodec/rka.c
@@ -723,16 +723,16 @@ static int decode_filter(RKAContext *s, ChContext *ctx, ACoder *ac, int off, uns
last_val = val;
src = &ctx->buf1[off + -1];
for (int i = 0; i < filt.size && i < 15; i++)
- sum += filt.coeffs[i] * src[-i];
+ sum += filt.coeffs[i] * (unsigned)src[-i];
sum = sum * 2;
for (int i = 15; i < filt.size; i++)
- sum += filt.coeffs[i] * src[-i];
+ sum += filt.coeffs[i] * (unsigned)src[-i];
sum = sum >> 6;
if (ctx->cmode == 0) {
if (bits == 0) {
ctx->buf1[off] = sum + val;
} else {
- ctx->buf1[off] = (val + (sum >> bits) << bits) +
+ ctx->buf1[off] = (val + (sum >> bits)) * (1 << bits) +
(((1U << bits) - 1U) & ctx->buf1[off + -1]);
}
ctx->buf0[off] = ctx->buf1[off] + ctx->buf0[off + -1];
--
2.17.1
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