From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: [PATCH V40 07/29] lockdown: Copy secure_boot flag in boot params across kexec reboot Date: Mon, 19 Aug 2019 17:17:43 -0700 Message-ID: <20190820001805.241928-8-matthewgarrett@google.com> References: <20190820001805.241928-1-matthewgarrett@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <20190820001805.241928-1-matthewgarrett@google.com> Sender: linux-kernel-owner@vger.kernel.org To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Dave Young , David Howells , Matthew Garrett , Kees Cook , kexec@lists.infradead.org List-Id: linux-api@vger.kernel.org From: Dave Young Kexec reboot in case secure boot being enabled does not keep the secure boot mode in new kernel, so later one can load unsigned kernel via legacy kexec_load. In this state, the system is missing the protections provided by secure boot. Adding a patch to fix this by retain the secure_boot flag in original kernel. secure_boot flag in boot_params is set in EFI stub, but kexec bypasses the stub. Fixing this issue by copying secure_boot flag across kexec reboot. Signed-off-by: Dave Young Signed-off-by: David Howells Signed-off-by: Matthew Garrett Reviewed-by: Kees Cook cc: kexec@lists.infradead.org Signed-off-by: James Morris --- arch/x86/kernel/kexec-bzimage64.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index f03237e3f192..5d64a22f99ce 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -180,6 +180,7 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr, if (efi_enabled(EFI_OLD_MEMMAP)) return 0; + params->secure_boot = boot_params.secure_boot; ei->efi_loader_signature = current_ei->efi_loader_signature; ei->efi_systab = current_ei->efi_systab; ei->efi_systab_hi = current_ei->efi_systab_hi; -- 2.23.0.rc1.153.gdeed80330f-goog