From 0c60d5c59fe05de80fc45e097c61b6f5487431de Mon Sep 17 00:00:00 2001 From: "Ronald S. Bultje" Date: Wed, 22 Feb 2012 16:48:38 -0800 Subject: [PATCH] swscale: take first/lastline over/underflows into account for MMX. Fixes crashes for extremely large resizes (several 100-fold). Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC: libav-stable@libav.org (cherry picked from commit 1d8c4af396b6ed84c84b5ebf0bf1163c4a7a3017) Signed-off-by: Anton Khirnov --- libswscale/x86/swscale_mmx.c | 38 ++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/libswscale/x86/swscale_mmx.c b/libswscale/x86/swscale_mmx.c index 867a9f1244..0853e12c41 100644 --- a/libswscale/x86/swscale_mmx.c +++ b/libswscale/x86/swscale_mmx.c @@ -132,6 +132,44 @@ void updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrBufI const int16_t **chrUSrcPtr= (const int16_t **) chrUPixBuf + chrBufIndex + firstChrSrcY - lastInChrBuf + vChrBufSize; const int16_t **alpSrcPtr= (CONFIG_SWSCALE_ALPHA && alpPixBuf) ? (const int16_t **) alpPixBuf + lumBufIndex + firstLumSrcY - lastInLumBuf + vLumBufSize : NULL; int i; + + if (firstLumSrcY < 0 || firstLumSrcY + vLumFilterSize > c->srcH) { + const int16_t **tmpY = (const int16_t **) lumPixBuf + 2 * vLumBufSize; + int neg = -firstLumSrcY, i, end = FFMIN(c->srcH - firstLumSrcY, vLumFilterSize); + for (i = 0; i < neg; i++) + tmpY[i] = lumSrcPtr[neg]; + for ( ; i < end; i++) + tmpY[i] = lumSrcPtr[i]; + for ( ; i < vLumFilterSize; i++) + tmpY[i] = tmpY[i-1]; + lumSrcPtr = tmpY; + + if (alpSrcPtr) { + const int16_t **tmpA = (const int16_t **) alpPixBuf + 2 * vLumBufSize; + for (i = 0; i < neg; i++) + tmpA[i] = alpSrcPtr[neg]; + for ( ; i < end; i++) + tmpA[i] = alpSrcPtr[i]; + for ( ; i < vLumFilterSize; i++) + tmpA[i] = tmpA[i - 1]; + alpSrcPtr = tmpA; + } + } + if (firstChrSrcY < 0 || firstChrSrcY + vChrFilterSize > c->chrSrcH) { + const int16_t **tmpU = (const int16_t **) chrUPixBuf + 2 * vChrBufSize; + int neg = -firstChrSrcY, i, end = FFMIN(c->chrSrcH - firstChrSrcY, vChrFilterSize); + for (i = 0; i < neg; i++) { + tmpU[i] = chrUSrcPtr[neg]; + } + for ( ; i < end; i++) { + tmpU[i] = chrUSrcPtr[i]; + } + for ( ; i < vChrFilterSize; i++) { + tmpU[i] = tmpU[i - 1]; + } + chrUSrcPtr = tmpU; + } + if (flags & SWS_ACCURATE_RND) { int s= APCK_SIZE / 8; for (i=0; i