x86: Sanity test on vesa parameters before setting up kernel screen_info

We should not set up kernel screen_info when the vesa parameters are
insane, otherwise kernel will panic.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pci/pci_rom.c b/drivers/pci/pci_rom.c
index a33efae..26db3ca 100644
--- a/drivers/pci/pci_rom.c
+++ b/drivers/pci/pci_rom.c
@@ -235,6 +235,10 @@
 #ifdef CONFIG_FRAMEBUFFER_SET_VESA_MODE
 	struct vesa_mode_info *vesa = &mode_info.vesa;
 
+	/* Sanity test on VESA parameters */
+	if (!vesa->x_resolution || !vesa->y_resolution)
+		return;
+
 	screen_info->orig_video_isVGA = VIDEO_TYPE_VLFB;
 
 	screen_info->lfb_width = vesa->x_resolution;