On Mon, Aug 02, 2021 at 05:40:57PM +0800, Michael Chang via Grub-devel wrote: > The gcc by default assumes executable stack is required if the source > object file doesn't have .note.GNU-stack section in place. If any of the > source objects doesn't incorporate the GNU-stack note, the resulting > program will have executable stack flag set in PT_GNU_STACK program > header to instruct program loader or kernel to set up the exeutable > stack when program loads to memory. > > Usually the .note.GNU-stack section will be generated by gcc > automatically if it finds that executable stack is not required. However > it doesn't take care of generating .note.GNU-stack section for those > object files built from assembler sources. This leads to unnecessary > risk of security of exploiting the executable stack because those > assembler sources don't actually require stack to be executable to work. > > The grub-emu and grub-emu-lite are found to flag stack as executable > revealed by execstack tool.
Did you test all executables for all supported architectures and platforms? > $ mkdir -p build-emu && cd build-emu > $ ../configure --with-platform=emu && make > $ execstack -q grub-core/grub-emu grub-core/grub-emu-lite > X grub-core/grub-emu > X grub-core/grub-emu-lite > > This patch will add the missing GNU-stack note to the assembler source > used by both utilities, therefore the result doesn't count on gcc > default behavior and the executable stack is disabled. > > $ execstack -q grub-core/grub-emu grub-core/grub-emu-lite > - grub-core/grub-emu > - grub-core/grub-emu-lite > > Signed-off-by: Michael Chang <mch...@suse.com> Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com> Daniel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
