| gst-ffmpeg: pngdec/filter: dont access out of array elements at the end |
| |
| Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind |
| |
| Upstream-Status: Backport |
| |
| Signed-off-by: Yue Tao <yue.tao@windriver.com> |
| --- |
| libavcodec/pngdec.c | 12 ++++-------- |
| 1 files changed, 4 insertions(+), 8 deletions(-) |
| |
| diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c |
| index 97c0ad1..193e35e 100644 |
| --- a/gst-libs/ext/libav/libavcodec/pngdec.c |
| +++ b/gst-libs/ext/libav/libavcodec/pngdec.c |
| @@ -190,7 +190,7 @@ void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w |
| if(bpp >= 2) g = dst[1];\ |
| if(bpp >= 3) b = dst[2];\ |
| if(bpp >= 4) a = dst[3];\ |
| - for(; i < size; i+=bpp) {\ |
| + for(; i <= size - bpp; i+=bpp) {\ |
| dst[i+0] = r = op(r, src[i+0], last[i+0]);\ |
| if(bpp == 1) continue;\ |
| dst[i+1] = g = op(g, src[i+1], last[i+1]);\ |
| @@ -206,13 +206,9 @@ void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w |
| else if(bpp == 2) UNROLL1(2, op)\ |
| else if(bpp == 3) UNROLL1(3, op)\ |
| else if(bpp == 4) UNROLL1(4, op)\ |
| - else {\ |
| - for (; i < size; i += bpp) {\ |
| - int j;\ |
| - for (j = 0; j < bpp; j++)\ |
| - dst[i+j] = op(dst[i+j-bpp], src[i+j], last[i+j]);\ |
| - }\ |
| - } |
| + for (; i < size; i++) {\ |
| + dst[i] = op(dst[i-bpp], src[i], last[i]);\ |
| + }\ |
| |
| /* NOTE: 'dst' can be equal to 'last' */ |
| static void png_filter_row(PNGDSPContext *dsp, uint8_t *dst, int filter_type, |
| -- |
| 1.7.5.4 |
| |