fs: binfmt_elf_efpic: don't use missing interpreter's properties

Static FDPIC executable may get an executable stack even when it has
non-executable GNU_STACK segment. This happens when STACK segment has rw
permissions, but does not specify stack size. In that case FDPIC loader
uses permissions of the interpreter's stack, and for static executables
with no interpreter it results in choosing the arch-default permissions
for the stack.

Fix that by using the interpreter's properties only when the interpreter
is actually used.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Link: https://lore.kernel.org/r/20240118150637.660461-1-jcmvbkbc@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Max Filippov 2024-01-18 07:06:37 -08:00 committed by Kees Cook
parent 41bccc98fb
commit 15fd1dc3da
1 changed files with 1 additions and 1 deletions

View File

@ -320,7 +320,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
else
executable_stack = EXSTACK_DEFAULT;
if (stack_size == 0) {
if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) {
stack_size = interp_params.stack_size;
if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
executable_stack = EXSTACK_ENABLE_X;