configs/hardening: Fix disabling UBSAN configurations

The initial change that added kernel/configs/hardening.config attempted
to disable all UBSAN sanitizers except for the array bounds one while
turning on UBSAN_TRAP. Unfortunately, it only got the syntax for
CONFIG_UBSAN_SHIFT correct, so configurations that are on by default
with CONFIG_UBSAN=y such as CONFIG_UBSAN_{BOOL,ENUM} do not get disabled
properly.

  CONFIG_ARCH_HAS_UBSAN=y
  CONFIG_UBSAN=y
  CONFIG_UBSAN_TRAP=y
  CONFIG_CC_HAS_UBSAN_BOUNDS_STRICT=y
  CONFIG_UBSAN_BOUNDS=y
  CONFIG_UBSAN_BOUNDS_STRICT=y
  # CONFIG_UBSAN_SHIFT is not set
  # CONFIG_UBSAN_DIV_ZERO is not set
  # CONFIG_UBSAN_UNREACHABLE is not set
  CONFIG_UBSAN_SIGNED_WRAP=y
  CONFIG_UBSAN_BOOL=y
  CONFIG_UBSAN_ENUM=y
  # CONFIG_TEST_UBSAN is not set

Add the missing 'is not set' to each configuration that needs it so that
they get disabled as intended.

  CONFIG_ARCH_HAS_UBSAN=y
  CONFIG_UBSAN=y
  CONFIG_UBSAN_TRAP=y
  CONFIG_CC_HAS_UBSAN_BOUNDS_STRICT=y
  CONFIG_UBSAN_BOUNDS=y
  CONFIG_UBSAN_BOUNDS_STRICT=y
  # CONFIG_UBSAN_SHIFT is not set
  # CONFIG_UBSAN_DIV_ZERO is not set
  # CONFIG_UBSAN_UNREACHABLE is not set
  CONFIG_UBSAN_SIGNED_WRAP=y
  # CONFIG_UBSAN_BOOL is not set
  # CONFIG_UBSAN_ENUM is not set
  # CONFIG_TEST_UBSAN is not set

Fixes: 215199e3d9f3 ("hardening: Provide Kconfig fragments for basic options")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240411-fix-ubsan-in-hardening-config-v1-1-e0177c80ffaa@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/kernel/configs/hardening.config b/kernel/configs/hardening.config
index 7a5bbfc024b7d0ee0c376f71474a0cca042c0824..d6f6dc45628aafa23a1ad7d8ac0fdfa81f23ac9c 100644 (file)
--- a/kernel/configs/hardening.config
+++ b/kernel/configs/hardening.config
@@ -39,11 +39,11 @@ CONFIG_UBSAN=y
 CONFIG_UBSAN_TRAP=y
 CONFIG_UBSAN_BOUNDS=y
 # CONFIG_UBSAN_SHIFT is not set
-# CONFIG_UBSAN_DIV_ZERO
-# CONFIG_UBSAN_UNREACHABLE
-# CONFIG_UBSAN_BOOL
-# CONFIG_UBSAN_ENUM
-# CONFIG_UBSAN_ALIGNMENT
+# CONFIG_UBSAN_DIV_ZERO is not set
+# CONFIG_UBSAN_UNREACHABLE is not set
+# CONFIG_UBSAN_BOOL is not set
+# CONFIG_UBSAN_ENUM is not set
+# CONFIG_UBSAN_ALIGNMENT is not set
 
 # Sampling-based heap out-of-bounds and use-after-free detection.
 CONFIG_KFENCE=y