numVisuals & numProps are both CARD32 and need to be bounds checked before multiplying by structure sizes to come up with the total size to allocate, to avoid integer overflow leading to underallocation and writing data from the network past the end of the allocated buffer.
Reported-by: Ilja Van Sprundel <[email protected]> Signed-off-by: Alan Coopersmith <[email protected]> --- hw/dmx/dmx_glxvisuals.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/hw/dmx/dmx_glxvisuals.c b/hw/dmx/dmx_glxvisuals.c index f903b74..027557a 100644 --- a/hw/dmx/dmx_glxvisuals.c +++ b/hw/dmx/dmx_glxvisuals.c @@ -37,6 +37,7 @@ #include <GL/glxproto.h> #include <X11/extensions/Xext.h> #include <X11/extensions/extutil.h> +#include <limits.h> #include "dmx_glxvisuals.h" @@ -84,7 +85,10 @@ GetGLXVisualConfigs(Display * dpy, int screen, int *nconfigs) SyncHandle(); return NULL; } - props = (INT32 *) Xmalloc(nprops * __GLX_SIZE_CARD32); + if (nprops < (INT_MAX / __GLX_SIZE_CARD32)) + props = Xmalloc(nprops * __GLX_SIZE_CARD32); + else + props = NULL; if (!props) { UnlockDisplay(dpy); SyncHandle(); @@ -92,15 +96,16 @@ GetGLXVisualConfigs(Display * dpy, int screen, int *nconfigs) } /* Allocate memory for our config structure */ - config = (__GLXvisualConfig *) - Xmalloc(nvisuals * sizeof(__GLXvisualConfig)); + if (nvisuals < (INT_MAX / sizeof(__GLXvisualConfig))) + config = Xcalloc(nvisuals, sizeof(__GLXvisualConfig)); + else + config = NULL; if (!config) { free(props); UnlockDisplay(dpy); SyncHandle(); return NULL; } - memset(config, 0, nvisuals * sizeof(__GLXvisualConfig)); configs = config; num_good_visuals = 0; -- 1.7.9.2 _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel
