aeff4a1dc1
In grub-module-verifierXX.c, the function find_section() uses the value from grub_target_to_host16 (e->e_shstrndx) to obtain the section header table index of the section name string table, but it wasn't being checked if the value was there. According to the elf(5) manual page, "If the index of section name string table section is larger than or equal to SHN_LORESERVE (0xff00), this member holds SHN_XINDEX (0xffff) and the real index of the section name string table section is held in the sh_link member of the initial entry in section header table. Otherwise, the sh_link member of the initial entry in section header table contains the value zero." Since this check wasn't being made, the function get_shstrndx() is being added to make this check and use e_shstrndx if it doesn't have SHN_XINDEX as a value, else use sh_link. We also need to make sure e_shstrndx isn't greater than or equal to SHN_LORESERVE and sh_link isn't less than SHN_LORESERVE. Note that it may look as though the argument *arch isn't being used, it's actually required in order to use the macros grub_target_to_host*(x) which are unwinded to grub_target_to_host*_real(arch, (x)) based on defines earlier in the file. Signed-off-by: Alec Brown <alec.r.brown@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.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'