From: Nathan Chancellor <nathan@xxxxxxxxxx> commit d6a9fb87e9d18f3394a9845546bbe868efdccfd2 upstream. A bad bug in clang's implementation of -fzero-call-used-regs can result in NULL pointer dereferences (see the links above the check for more information). Restrict CONFIG_CC_HAS_ZERO_CALL_USED_REGS to either a supported GCC version or a clang newer than 15.0.6, which will catch both a theoretical 15.0.7 and the upcoming 16.0.0, which will both have the bug fixed. Cc: stable@xxxxxxxxxxxxxxx # v5.15+ Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221214232602.4118147-1-nathan@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- security/Kconfig.hardening | 3 +++ 1 file changed, 3 insertions(+) --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -253,6 +253,9 @@ config INIT_ON_FREE_DEFAULT_ON config CC_HAS_ZERO_CALL_USED_REGS def_bool $(cc-option,-fzero-call-used-regs=used-gpr) + # https://github.com/ClangBuiltLinux/linux/issues/1766 + # https://github.com/llvm/llvm-project/issues/59242 + depends on !CC_IS_CLANG || CLANG_VERSION > 150006 config ZERO_CALL_USED_REGS bool "Enable register zeroing on function exit"
