14ceb3b3ff
Loaders rely on global variables for saving context which is consumed in the boot hook and freed in the unload hook. In the case where a loader command is executed twice, calling grub_loader_set() a second time executes the unload hook, but in some cases this runs when the loader's global context has already been updated, resulting in the updated context being freed and potential use-after-free bugs when the boot hook is subsequently called. This adds a new API, grub_loader_set_ex(), which allows a loader to specify context that is passed to its boot and unload hooks. This is an alternative to requiring that loaders call grub_loader_unset() before mutating their global context. Signed-off-by: Chris Coulson <chris.coulson@canonical.com> 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. See the file MAINTAINERS for information about the GRUB maintainers, etc. If you found a security vulnerability in the GRUB please check the SECURITY file to get more information how to properly report this kind of bugs to the maintainers. 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'