Commit dae2ce36 authored by Ronald S. Bultje's avatar Ronald S. Bultje
Browse files

swscale: enforce a minimum filtersize.

At very small dimensions, this calculation could lead to zero-sized
filters, which leads to uninitialized output, zero-sized allocations,
loop overflows in SIMD that uses do{..}while(i++<filtersize); instead
of for(i=0;i<filtersize;i++){..} and several other similar failures.
Therefore, require a minimum filtersize of 1.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
parent 764852d6
......@@ -263,7 +263,7 @@ static int initFilter(int16_t **outFilter, int16_t **filterPos, int *outFilterSi
if (xInc <= 1<<16) filterSize= 1 + sizeFactor; // upscale
else filterSize= 1 + (sizeFactor*srcW + dstW - 1)/ dstW;
if (filterSize > srcW-2) filterSize=srcW-2;
filterSize = av_clip(filterSize, 1, srcW - 2);
FF_ALLOC_OR_GOTO(NULL, filter, dstW*sizeof(*filter)*filterSize, fail);
......
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