tis 2022-09-27 klockan 03:47 +0200 skrev Andreas Rheinhardt:
Affected the jpeg2000dsp checkasm test.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> --- libavcodec/jpeg2000dsp.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/libavcodec/jpeg2000dsp.c b/libavcodec/jpeg2000dsp.c index b61be3b72f..b1bff6d5b1 100644 --- a/libavcodec/jpeg2000dsp.c +++ b/libavcodec/jpeg2000dsp.c @@ -76,14 +76,13 @@ static void ict_int(void *_src0, void *_src1, void *_src2, int csize) static void rct_int(void *_src0, void *_src1, void *_src2, int csize) { - int32_t *src0 = _src0, *src1 = _src1, *src2 = _src2; - int32_t i0, i1, i2; + uint32_t *src0 = _src0, *src1 = _src1, *src2 = _src2; int i; for (i = 0; i < csize; i++) { - i1 = *src0 - (*src2 + *src1 >> 2); - i0 = i1 + *src2; - i2 = i1 + *src1; + uint32_t i1 = *src0 - ((int32_t)(*src2 + *src1) >> 2);
The addition could conceivably overflow. Also could just use / 4 instead of >> 2.
+ int32_t i0 = i1 + *src2; + int32_t i2 = i1 + *src1;
These could also overflow. And agian, not in typical use obviously because this is for lossless, but for malicious files possibly. /Tomas