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@vger.kernel.org # v5.15+ Signed-off-by: Nathan Chancellor nathan@kernel.org --- security/Kconfig.hardening | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index d766b7d0ffd1..53baa95cb644 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -257,6 +257,9 @@ 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"

base-commit: 830b3c68c1fb1e9176028d02ef86f3cf76aa2476