Several small signedness / overflow corrections to qxl_create_guest_primary: 1. use 64 bit unsigned for size to avoid overflow possible from two 32 bit multiplicants. 2. correct sign for requested_height 3. add a more verbose error message when setting guest bug state (which causes a complete guess blackout until reset, so it helps if it is verbose).
Signed-off-by: Alon Levy <al...@redhat.com> --- hw/display/qxl.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/hw/display/qxl.c b/hw/display/qxl.c index e4f172e..ceae1d9 100644 --- a/hw/display/qxl.c +++ b/hw/display/qxl.c @@ -19,6 +19,7 @@ */ #include <zlib.h> +#include <stdint.h> #include "qemu-common.h" #include "qemu/timer.h" @@ -1360,14 +1361,16 @@ static void qxl_create_guest_primary(PCIQXLDevice *qxl, int loadvm, { QXLDevSurfaceCreate surface; QXLSurfaceCreate *sc = &qxl->guest_primary.surface; - int size; - int requested_height = le32_to_cpu(sc->height); + uint32_t requested_height = le32_to_cpu(sc->height); int requested_stride = le32_to_cpu(sc->stride); - size = abs(requested_stride) * requested_height; - if (size > qxl->vgamem_size) { - qxl_set_guest_bug(qxl, "%s: requested primary larger then framebuffer" - " size", __func__); + if (requested_stride == INT32_MIN || + abs(requested_stride) * (uint64_t)requested_height + > qxl->vgamem_size) { + qxl_set_guest_bug(qxl, "%s: requested primary larger than framebuffer" + " stride %d x height %" PRIu32 " > %" PRIu32, + __func__, requested_stride, requested_height, + qxl->vgamem_size); return; } -- 1.8.4.2