From 1895d414aaacece3b57d7bf19502305e9a064fae Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 24 Feb 2015 00:32:39 +0100 Subject: [PATCH] swscale/utils: More carefully merge and clear coefficients outside the input Fixes out of array read Fixes: asan_heap-oob_35ca682_1474_cov_3230122439_aletrek_tga_16bit.mov Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libswscale/utils.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/libswscale/utils.c b/libswscale/utils.c index c09d37d98a..b63ab190a6 100644 --- a/libswscale/utils.c +++ b/libswscale/utils.c @@ -612,14 +612,24 @@ static av_cold int initFilter(int16_t **outFilter, int32_t **filterPos, if ((*filterPos)[i] + filterSize > srcW) { int shift = (*filterPos)[i] + FFMIN(filterSize - srcW, 0); + int64_t acc = 0; - // move filter coefficients right to compensate for filterPos - for (j = filterSize - 2; j >= 0; j--) { - int right = FFMIN(j + shift, filterSize - 1); - filter[i * filterSize + right] += filter[i * filterSize + j]; - filter[i * filterSize + j] = 0; + for (j = filterSize - 1; j >= 0; j--) { + if ((*filterPos)[i] + j >= srcW) { + acc += filter[i * filterSize + j]; + filter[i * filterSize + j] = 0; + } } + for (j = filterSize - 1; j >= 0; j--) { + if (j < shift) { + filter[i * filterSize + j] = 0; + } else { + filter[i * filterSize + j] = filter[i * filterSize + j - shift]; + } + } + (*filterPos)[i]-= shift; + filter[i * filterSize + srcW - 1 - (*filterPos)[i]] += acc; } }