From ed1e13a1f4e316bcf0dc0d4b2c16b1df3f075005 Mon Sep 17 00:00:00 2001 From: Alan Coopersmith Date: Wed, 22 Jan 2014 22:37:15 -0800 Subject: [PATCH 21/40] dix: integer overflow in RegionSizeof() [CVE-2014-8092 3/4] RegionSizeof contains several integer overflows if a large length value is passed in. Once we fix it to return 0 on overflow, we also have to fix the callers to handle this error condition v2: Fixed limit calculation in RegionSizeof as pointed out by jcristau. v3: backport to nx-libs 3.6.x (Mike DePaulo) Reported-by: Ilja Van Sprundel Signed-off-by: Alan Coopersmith Reviewed-by: Peter Hutterer Reviewed-by: Julien Cristau Conflicts: dix/region.c include/regionstr.h --- nx-X11/programs/Xserver/include/regionstr.h | 10 +++++--- nx-X11/programs/Xserver/mi/miregion.c | 39 ++++++++++++++++++++--------- 2 files changed, 34 insertions(+), 15 deletions(-) diff --git a/nx-X11/programs/Xserver/include/regionstr.h b/nx-X11/programs/Xserver/include/regionstr.h index 000bf3f..cf41170 100644 --- a/nx-X11/programs/Xserver/include/regionstr.h +++ b/nx-X11/programs/Xserver/include/regionstr.h @@ -53,6 +53,9 @@ SOFTWARE. typedef struct _Region RegionRec, *RegionPtr; +#include +#include + #include "miscstruct.h" /* Return values from RectIn() */ @@ -93,7 +96,7 @@ extern RegDataRec miBrokenData; #define REGION_BOX(reg,i) (®ION_BOXPTR(reg)[i]) #define REGION_TOP(reg) REGION_BOX(reg, (reg)->data->numRects) #define REGION_END(reg) REGION_BOX(reg, (reg)->data->numRects - 1) -#define REGION_SZOF(n) (sizeof(RegDataRec) + ((n) * sizeof(BoxRec))) +#define REGION_SZOF(n) (n < ((INT_MAX - sizeof(RegDataRec)) / sizeof(BoxRec)) ? sizeof(RegDataRec) + ((n) * sizeof(BoxRec)) : 0) /* Keith recommends weaning the region code of pScreen argument */ #define REG_pScreen screenInfo.screens[0] @@ -257,9 +260,10 @@ extern RegDataRec miBrokenData; } \ else \ { \ + size_t rgnSize; \ (_pReg)->extents = miEmptyBox; \ - if (((_size) > 1) && ((_pReg)->data = \ - (RegDataPtr)xalloc(REGION_SZOF(_size)))) \ + if (((_size) > 1) && ((rgnSize = REGION_SZOF(_size)) > 0) && \ + ((_pReg)->data = (RegDataPtr)xalloc(rgnSize))) \ { \ (_pReg)->data->size = (_size); \ (_pReg)->data->numRects = 0; \ diff --git a/nx-X11/programs/Xserver/mi/miregion.c b/nx-X11/programs/Xserver/mi/miregion.c index df33248..5ec4ec5 100644 --- a/nx-X11/programs/Xserver/mi/miregion.c +++ b/nx-X11/programs/Xserver/mi/miregion.c @@ -172,7 +172,6 @@ Equipment Corporation. ((r1)->y1 <= (r2)->y1) && \ ((r1)->y2 >= (r2)->y2) ) -#define xallocData(n) (RegDataPtr)xalloc(REGION_SZOF(n)) #define xfreeData(reg) if ((reg)->data && (reg)->data->size) xfree((reg)->data) #define RECTALLOC_BAIL(pReg,n,bail) \ @@ -209,8 +208,9 @@ if (!(pReg)->data || (((pReg)->data->numRects + (n)) > (pReg)->data->size)) \ #define DOWNSIZE(reg,numRects) \ if (((numRects) < ((reg)->data->size >> 1)) && ((reg)->data->size > 50)) \ { \ - RegDataPtr NewData; \ - NewData = (RegDataPtr)xrealloc((reg)->data, REGION_SZOF(numRects)); \ + size_t NewSize = REGION_SZOF(numRects); \ + RegDataPtr NewData = \ + (NewSize > 0) ? (RegDataPtr)xrealloc((reg)->data, NewSize) : NULL; \ if (NewData) \ { \ NewData->size = (numRects); \ @@ -337,7 +337,7 @@ miRegionCreate(rect, size) int size; { register RegionPtr pReg; - + size_t newSize; pReg = (RegionPtr)xalloc(sizeof(RegionRec)); if (!pReg) return &miBrokenRegion; @@ -349,7 +349,9 @@ miRegionCreate(rect, size) else { pReg->extents = miEmptyBox; - if ((size > 1) && (pReg->data = xallocData(size))) + newSize = REGION_SZOF(size); + if ((size > 1) && (newSize > 0) && + (pReg->data = xalloc(newSize))) { pReg->data->size = size; pReg->data->numRects = 0; @@ -371,6 +373,8 @@ miRegionInit(pReg, rect, size) BoxPtr rect; int size; { + size_t newSize; + if (rect) { pReg->extents = *rect; @@ -379,7 +383,9 @@ miRegionInit(pReg, rect, size) else { pReg->extents = miEmptyBox; - if ((size > 1) && (pReg->data = xallocData(size))) + newSize = REGION_SZOF(size); + if ((size > 1) && (newSize > 0) && + (pReg->data = xalloc(newSize))) { pReg->data->size = size; pReg->data->numRects = 0; @@ -423,11 +429,13 @@ miRectAlloc( int n) { RegDataPtr data; + size_t rgnSize; if (!pRgn->data) { n++; - pRgn->data = xallocData(n); + rgnSize = REGION_SZOF(n); + pRgn->data = (rgnSize > 0) ? xalloc(rgnSize) : NULL; if (!pRgn->data) return miRegionBreak (pRgn); pRgn->data->numRects = 1; @@ -435,7 +443,8 @@ miRectAlloc( } else if (!pRgn->data->size) { - pRgn->data = xallocData(n); + rgnSize = REGION_SZOF(n); + pRgn->data = (rgnSize > 0) ? xalloc(rgnSize) : NULL; if (!pRgn->data) return miRegionBreak (pRgn); pRgn->data->numRects = 0; @@ -449,7 +458,8 @@ miRectAlloc( n = 250; } n += pRgn->data->numRects; - data = (RegDataPtr)xrealloc(pRgn->data, REGION_SZOF(n)); + rgnSize = REGION_SZOF(n); + data = (rgnSize > 0) ? xrealloc(pRgn->data, rgnSize) : NULL; if (!data) return miRegionBreak (pRgn); pRgn->data = data; @@ -476,8 +486,10 @@ miRegionCopy(dst, src) } if (!dst->data || (dst->data->size < src->data->numRects)) { + size_t newSize = REGION_SZOF(src->data->numRects); xfreeData(dst); - dst->data = xallocData(src->data->numRects); + + dst->data = newSize > 0 ? xalloc(newSize) : NULL; if (!dst->data) return miRegionBreak (dst); dst->data->size = src->data->numRects; @@ -1667,6 +1679,7 @@ miRectsToRegion(nrects, prect, ctype) register BoxPtr pBox; register int i; int x1, y1, x2, y2; + size_t newSize; pRgn = miRegionCreate(NullBox, 0); if (REGION_NAR (pRgn)) @@ -1691,7 +1704,8 @@ miRectsToRegion(nrects, prect, ctype) } return pRgn; } - pData = xallocData(nrects); + newSize = REGION_SZOF(nrects); + pData = newSize > 0 ? xalloc(newSize) : NULL; if (!pData) { miRegionBreak (pRgn); @@ -2206,8 +2220,9 @@ miRegionDataCopy( } if (!dst->data || (dst->data->size < src->data->numRects)) { + size_t newSize = REGION_SZOF(src->data->numRects); xfreeData(dst); - dst->data = xallocData(src->data->numRects); + dst->data = newSize > 0 ? xalloc(newSize) : NULL; if (!dst->data) return miRegionBreak (dst); } -- 2.1.4