7630ec5397
When a module is attempted to be removed its reference counter is always decremented. This means that repeated rmmod invocations will cause the module to be unloaded even if another module depends on it. This may lead to a use-after-free scenario allowing an attacker to execute arbitrary code and by-pass the UEFI Secure Boot protection. While being there, add the extern keyword to some function declarations in that header file. Fixes: CVE-2020-25632 Reported-by: Chris Coulson <chris.coulson@canonical.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.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. 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'