To reduce stale data lifetimes, enable CONFIG_INIT_ON_FREE_DEFAULT_ON as well. This matches the addition of CONFIG_STACKLEAK=y, which is doing similar for stack memory.
Signed-off-by: Kees Cook kees@kernel.org --- Cc: "Gustavo A. R. Silva" gustavoars@kernel.org Cc: linux-hardening@vger.kernel.org --- kernel/configs/hardening.config | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/configs/hardening.config b/kernel/configs/hardening.config index d24c2772d04d..64caaf997fc0 100644 --- a/kernel/configs/hardening.config +++ b/kernel/configs/hardening.config @@ -60,6 +60,9 @@ CONFIG_LIST_HARDENED=y # Initialize all heap variables to zero on allocation. CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y
+# Initialize all heap variables to zero on free to reduce stale data lifetime. +CONFIG_INIT_ON_FREE_DEFAULT_ON=y + # Initialize all stack variables to zero on function entry. CONFIG_INIT_STACK_ALL_ZERO=y