132ddc42c7
The shim_lock module registers a verifier to call shim's verify, but the handler is registered even when the shim_lock protocol was not installed. This doesn't cause a NULL pointer dereference in shim_lock_write() because the shim_lock_init() function just returns GRUB_ERR_NONE if sl isn't set. But in that case there's no point to even register the shim_lock verifier since won't do anything. Additionally, it is only useful when Secure Boot is enabled. Finally, don't assume that the shim_lock protocol will always be present when the shim_lock_write() function is called, and check for it on every call to this function. Reported-by: Michael Chang <mchang@suse.com> Reported-by: Peter Jones <pjones@redhat.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'