linux-kernel - [PATCH v7 11/13] reboot: Secure Launch SEXIT support on reboot paths

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20231110222751.219836-12-ross.philipson@oracle.com>
Date:   Fri, 10 Nov 2023 17:27:49 -0500
From:   Ross Philipson <ross.philipson@...cle.com>
To:     linux-kernel@...r.kernel.org, x86@...nel.org,
        linux-integrity@...r.kernel.org, linux-doc@...r.kernel.org,
        linux-crypto@...r.kernel.org, iommu@...ts.linux-foundation.org,
        kexec@...ts.infradead.org, linux-efi@...r.kernel.org
Cc:     ross.philipson@...cle.com, dpsmith@...rtussolutions.com,
        tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        ardb@...nel.org, mjg59@...f.ucam.org,
        James.Bottomley@...senpartnership.com, luto@...capital.net,
        nivedita@...m.mit.edu, kanth.ghatraju@...cle.com,
        trenchboot-devel@...glegroups.com
Subject: [PATCH v7 11/13] reboot: Secure Launch SEXIT support on reboot paths

If the MLE kernel is being powered off, rebooted or halted,
then SEXIT must be called. Note that the SEXIT GETSEC leaf
can only be called after a machine_shutdown() has been done on
these paths. The machine_shutdown() is not called on a few paths
like when poweroff action does not have a poweroff callback (into
ACPI code) or when an emergency reset is done. In these cases,
just the TXT registers are finalized but SEXIT is skipped.

Signed-off-by: Ross Philipson <ross.philipson@...cle.com>
---
 arch/x86/kernel/reboot.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 830425e6d38e..668cfc5e4c92 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -12,6 +12,7 @@
 #include <linux/delay.h>
 #include <linux/objtool.h>
 #include <linux/pgtable.h>
+#include <linux/slaunch.h>
 #include <acpi/reboot.h>
 #include <asm/io.h>
 #include <asm/apic.h>
@@ -766,6 +767,7 @@ static void native_machine_restart(char *__unused)
 
 	if (!reboot_force)
 		machine_shutdown();
+	slaunch_finalize(!reboot_force);
 	__machine_emergency_restart(0);
 }
 
@@ -776,6 +778,9 @@ static void native_machine_halt(void)
 
 	tboot_shutdown(TB_SHUTDOWN_HALT);
 
+	/* SEXIT done after machine_shutdown() to meet TXT requirements */
+	slaunch_finalize(1);
+
 	stop_this_cpu(NULL);
 }
 
@@ -784,8 +789,12 @@ static void native_machine_power_off(void)
 	if (kernel_can_power_off()) {
 		if (!reboot_force)
 			machine_shutdown();
+		slaunch_finalize(!reboot_force);
 		do_kernel_power_off();
+	} else {
+		slaunch_finalize(0);
 	}
+
 	/* A fallback in case there is no PM info available */
 	tboot_shutdown(TB_SHUTDOWN_HALT);
 }
@@ -813,6 +822,7 @@ void machine_shutdown(void)
 
 void machine_emergency_restart(void)
 {
+	slaunch_finalize(0);
 	__machine_emergency_restart(1);
 }
 
-- 
2.39.3