From: Eric Biggers <ebiggers@google.com>

Date: Tue, 7 Feb 2023 22:51:33 -0800

Subject: [PATCH] randstruct: disable Clang 15 support

References: bsc#1012628

Patch-mainline: 6.2.1

Git-commit: 78f7a3fd6dc66cb788c21d7705977ed13c879351

commit 78f7a3fd6dc66cb788c21d7705977ed13c879351 upstream.

The randstruct support released in Clang 15 is unsafe to use due to a

bug that can cause miscompilations: "-frandomize-layout-seed

inconsistently randomizes all-function-pointers structs"

(https://github.com/llvm/llvm-project/issues/60349).  It has been fixed

on the Clang 16 release branch, so add a Clang version check.

Fixes: 035f7f87b729 ("randstruct: Enable Clang support")

Cc: stable@vger.kernel.org

Signed-off-by: Eric Biggers <ebiggers@google.com>

Acked-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

Reviewed-by: Bill Wendling <morbo@google.com>

Signed-off-by: Kees Cook <keescook@chromium.org>

Link: https://lore.kernel.org/r/20230208065133.220589-1-ebiggers@kernel.org

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 security/Kconfig.hardening | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening

index 53baa95c..0f295961 100644

--- a/security/Kconfig.hardening

+++ b/security/Kconfig.hardening

@@ -281,6 +281,9 @@ endmenu

 config CC_HAS_RANDSTRUCT

 	def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null)

+	# Randstruct was first added in Clang 15, but it isn't safe to use until

+	# Clang 16 due to https://github.com/llvm/llvm-project/issues/60349

+	depends on !CC_IS_CLANG || CLANG_VERSION >= 160000

 choice

 	prompt "Randomize layout of sensitive kernel structures"

-- 

2.35.3