linux-kernel - [PATCH v2 12/12] iommu: Do not allow IOMMU passthrough with Secure Launch

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]

Date:   Fri, 18 Jun 2021 12:12:57 -0400
From:   Ross Philipson <ross.philipson@...cle.com>
To:     linux-kernel@...r.kernel.org, x86@...nel.org,
        iommu@...ts.linux-foundation.org, linux-integrity@...r.kernel.org,
        linux-doc@...r.kernel.org
Cc:     ross.philipson@...cle.com, dpsmith@...rtussolutions.com,
        tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        luto@...capital.net, trenchboot-devel@...glegroups.com
Subject: [PATCH v2 12/12] iommu: Do not allow IOMMU passthrough with Secure Launch

The IOMMU should always be set to default translated type after
the PMRs are disabled to protect the MLE from DMA.

Signed-off-by: Ross Philipson <ross.philipson@...cle.com>
---
 drivers/iommu/intel/iommu.c | 5 +++++
 drivers/iommu/iommu.c       | 6 +++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index be35284..4f0256d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -41,6 +41,7 @@
 #include <linux/dma-direct.h>
 #include <linux/crash_dump.h>
 #include <linux/numa.h>
+#include <linux/slaunch.h>
 #include <asm/irq_remapping.h>
 #include <asm/cacheflush.h>
 #include <asm/iommu.h>
@@ -2877,6 +2878,10 @@ static bool device_is_rmrr_locked(struct device *dev)
  */
 static int device_def_domain_type(struct device *dev)
 {
+	/* Do not allow identity domain when Secure Launch is configured */
+	if (slaunch_get_flags() & SL_FLAG_ACTIVE)
+		return IOMMU_DOMAIN_DMA;
+
 	if (dev_is_pci(dev)) {
 		struct pci_dev *pdev = to_pci_dev(dev);
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 808ab70d..d49b7dd 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -23,6 +23,7 @@
 #include <linux/property.h>
 #include <linux/fsl/mc.h>
 #include <linux/module.h>
+#include <linux/slaunch.h>
 #include <trace/events/iommu.h>
 
 static struct kset *iommu_group_kset;
@@ -2761,7 +2762,10 @@ void iommu_set_default_passthrough(bool cmd_line)
 {
 	if (cmd_line)
 		iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API;
-	iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
+
+	/* Do not allow identity domain when Secure Launch is configured */
+	if (!(slaunch_get_flags() & SL_FLAG_ACTIVE))
+		iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
 }
 
 void iommu_set_default_translated(bool cmd_line)
-- 
1.8.3.1