The following commit has been merged into the core/core branch of tip: Commit-ID: 6e0d6ac5f3d9d90271899f6d340872360fe1caee Gitweb: https://git.kernel.org/tip/6e0d6ac5f3d9d90271899f6d340872360fe1caee Author: Kees Cook <keescook@xxxxxxxxxxxx> AuthorDate: Thu, 26 Mar 2020 23:48:20 -07:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Mon, 20 Apr 2020 19:44:27 +02:00 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 <hecmargi@xxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Link: https://lkml.kernel.org/r/20200327064820.12602-7-keescook@xxxxxxxxxxxx --- arch/arm64/include/asm/elf.h | 4 ++-- fs/compat_binfmt_elf.c | 5 +++++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 0074e9f..0e7df6f 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 aaad4ca..3068d57 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
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