Codes for KUSER_HELPERS can be abused as ROP gadaget,
So that It's better to disable that as if possible.
Since over ARMv6 has ldrex/strex at user-space,
NEED_KUSER_HELPERS is not selected for over ARMv6.
But, Even though NEED_KUSER_HELPERS is not selected,
current configuration enable KUSER_HELPERS as default.
- Enable KUSER_HELPERS as default even though over ARMv6.
- User can disable KUSER_HELPERS.
- Disable KUSER_HELPERS in ARMv6 or later as default.
- User can enable KUSER_HELPERS for compatibility.
This change removes the unnecessary configuration that has security-risk.
Signed-off-by: Jinbum Park <jinb.pa...@gmail.com>
arch/arm/mm/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 7f14acf..40e5fe5 100644
@@ -840,7 +840,7 @@ config NEED_KUSER_HELPERS
bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS
depends on MMU
- default y
+ default y if NEED_KUSER_HELPERS
Warning: disabling this option may break user programs.