numFBConfigs & numAttribs are CARD32s 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 <ivansprun...@ioactive.com> Signed-off-by: Alan Coopersmith <alan.coopersm...@oracle.com> --- hw/dmx/dmx_glxvisuals.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/hw/dmx/dmx_glxvisuals.c b/hw/dmx/dmx_glxvisuals.c index 027557a..56bd67b 100644 --- a/hw/dmx/dmx_glxvisuals.c +++ b/hw/dmx/dmx_glxvisuals.c @@ -279,7 +279,10 @@ GetGLXFBConfigs(Display * dpy, int glxMajorOpcode, int *nconfigs) return NULL; } - attrs = (INT32 *) Xmalloc(2 * numAttribs * __GLX_SIZE_CARD32); + if (numAttribs < (INT_MAX / (2 * __GLX_SIZE_CARD32))) + attrs = Xmalloc(2 * numAttribs * __GLX_SIZE_CARD32); + else + attrs = NULL; if (!attrs) { UnlockDisplay(dpy); SyncHandle(); @@ -287,15 +290,16 @@ GetGLXFBConfigs(Display * dpy, int glxMajorOpcode, int *nconfigs) } /* Allocate memory for our config structure */ - config = (__GLXFBConfig *) - Xmalloc(numFBConfigs * sizeof(__GLXFBConfig)); + if (numFBConfigs < (INT_MAX / sizeof(__GLXFBConfig))) + config = Xcalloc(numFBConfigs, sizeof(__GLXFBConfig)); + else + config = NULL; if (!config) { free(attrs); UnlockDisplay(dpy); SyncHandle(); return NULL; } - memset(config, 0, numFBConfigs * sizeof(__GLXFBConfig)); fbconfigs = config; /* Convert attribute list into our format */ -- 1.7.9.2 _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel