From 9347326d28fffc7534cad0b084539e936aacfd45 Mon Sep 17 00:00:00 2001 From: Peter Hutterer Date: Wed, 18 Jul 2018 13:22:43 +1000 Subject: [PATCH] Xext: dynamically allocate the PanoramiXDepths[j].vids array Control flow is: PanoramiXMaybeAddDepth() allocates an array size 240 (pDepth->numVisuals) PanoramiXMaybeAddVisual() finds up to 270 matches (pScreen->numVisuals) and writes those into the previously allocated array. This caused invalid reads/writes followed by eventually a double-free abort. Reproduced with xorg-integration-tests server test XineramaTest.ScreenCrossing/* (and a bunch of others). Signed-off-by: Peter Hutterer Reviewed-by: Keith Packard (cherry picked from commit 93cafb0828d2e24bd14616df1aa9883fb843dd6c) --- Xext/panoramiX.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/Xext/panoramiX.c b/Xext/panoramiX.c index 844ea49ce..bd9c45b03 100644 --- a/Xext/panoramiX.c +++ b/Xext/panoramiX.c @@ -751,11 +751,7 @@ PanoramiXMaybeAddDepth(DepthPtr pDepth) PanoramiXNumDepths, sizeof(DepthRec)); PanoramiXDepths[j].depth = pDepth->depth; PanoramiXDepths[j].numVids = 0; - /* XXX suboptimal, should grow these dynamically */ - if (pDepth->numVids) - PanoramiXDepths[j].vids = xallocarray(pDepth->numVids, sizeof(VisualID)); - else - PanoramiXDepths[j].vids = NULL; + PanoramiXDepths[j].vids = NULL; } static void @@ -796,6 +792,9 @@ PanoramiXMaybeAddVisual(VisualPtr pVisual) for (k = 0; k < PanoramiXNumDepths; k++) { if (PanoramiXDepths[k].depth == pVisual->nplanes) { + PanoramiXDepths[k].vids = reallocarray(PanoramiXDepths[k].vids, + PanoramiXDepths[k].numVids + 1, + sizeof(VisualID)); PanoramiXDepths[k].vids[PanoramiXDepths[k].numVids] = pVisual->vid; PanoramiXDepths[k].numVids++; break;