829329bddb
Catch the case where we have a font so big that it causes the number of rows or columns to be 0. Currently we continue and allocate a virtual_screen.text_buffer of size 0. We then try to use that for glpyhs and things go badly. On the emu platform, malloc() may give us a valid pointer, in which case we'll access heap memory which we shouldn't. Alternatively, it may give us NULL, in which case we'll crash. For other platforms, if I understand grub_memalign() correctly, we will receive a valid but small allocation that we will very likely later overrun. Prevent the creation of a virtual screen that isn't at least 40 cols by 12 rows. This is arbitrary, but it seems that if your width or height is half a standard 80x24 terminal, you're probably going to struggle to read anything anyway. Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This is GRUB 2, the second version of the GRand Unified Bootloader. GRUB 2 is rewritten from scratch to make GNU GRUB cleaner, safer, more robust, more powerful, and more portable. See the file NEWS for a description of recent changes to GRUB 2. See the file INSTALL for instructions on how to build and install the GRUB 2 data and program files. Please visit the official web page of GRUB 2, for more information. The URL is <http://www.gnu.org/software/grub/grub.html>. More extensive documentation is available in the Info manual, accessible using 'info grub' after building and installing GRUB 2. There are a number of important user-visible differences from the first version of GRUB, now known as GRUB Legacy. For a summary, please see: info grub Introduction 'Changes from GRUB Legacy'