From: Kees Cook Date: Fri, 27 Mar 2020 06:48:20 +0000 (-0700) Subject: arm64/elf: Disable automatic READ_IMPLIES_EXEC for 64-bit address spaces X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6e0d6ac5f3d9d90271899f6d340872360fe1caee;p=linux.git arm64/elf: Disable automatic READ_IMPLIES_EXEC for 64-bit address spaces With arm64 64-bit environments, there should never be a need for automatic READ_IMPLIES_EXEC, as the architecture has always been execute-bit aware (as in, the default memory protection should be NX unless a region explicitly requests to be executable). Suggested-by: Hector Marco-Gisbert Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Reviewed-by: Jason Gunthorpe Reviewed-by: Catalin Marinas Link: https://lkml.kernel.org/r/20200327064820.12602-7-keescook@chromium.org --- diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 0074e9fd64318..0e7df6f1eb7a9 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -105,7 +105,7 @@ *              CPU*: | arm32    | arm64 | * ELF:              |            |            | * ---------------------|------------|------------| - * missing PT_GNU_STACK | exec-all   | exec-all   | + * missing PT_GNU_STACK | exec-all   | exec-none  | * PT_GNU_STACK == RWX  | exec-stack | exec-stack | * PT_GNU_STACK == RW   | exec-none | exec-none | * @@ -117,7 +117,7 @@ * *all arm64 CPUs support NX, so there is no "lacks NX" column. * */ -#define elf_read_implies_exec(ex, stk) (stk == EXSTACK_DEFAULT) +#define compat_elf_read_implies_exec(ex, stk) (stk == EXSTACK_DEFAULT) #define CORE_DUMP_USE_REGSET #define ELF_EXEC_PAGESIZE PAGE_SIZE diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index aaad4ca1217ef..3068d57436b36 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -113,6 +113,11 @@ #define arch_setup_additional_pages compat_arch_setup_additional_pages #endif +#ifdef compat_elf_read_implies_exec +#undef elf_read_implies_exec +#define elf_read_implies_exec compat_elf_read_implies_exec +#endif + /* * Rename a few of the symbols that binfmt_elf.c will define. * These are all local so the names don't really matter, but it