From a1bc22d04dcf5ff5fbdd537c4a6d12cdd6533ff7 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Tue, 7 Feb 2023 22:51:33 -0800
Subject: [PATCH] randstruct: disable Clang 15 support
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>
---
security/Kconfig.hardening | 3 +++
1 file changed, 3 insertions(+)
diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
index 53baa95cb644f..0f295961e7736 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"