1389 lines
43 KiB
Diff
1389 lines
43 KiB
Diff
From 57c0dbcbafaa724313c672830ff0087f56a84c47 Mon Sep 17 00:00:00 2001
|
|
From: Matthew Garrett <mjg@redhat.com>
|
|
Date: Thu, 20 Sep 2012 10:40:56 -0400
|
|
Subject: [PATCH 01/14] Secure boot: Add new capability
|
|
|
|
Secure boot adds certain policy requirements, including that root must not
|
|
be able to do anything that could cause the kernel to execute arbitrary code.
|
|
The simplest way to handle this would seem to be to add a new capability
|
|
and gate various functionality on that. We'll then strip it from the initial
|
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capability set if required.
|
|
|
|
Signed-off-by: Matthew Garrett <mjg@redhat.com>
|
|
---
|
|
include/uapi/linux/capability.h | 6 +++++-
|
|
1 file changed, 5 insertions(+), 1 deletion(-)
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|
|
|
diff --git a/include/linux/capability.h b/include/linux/capability.h
|
|
index d10b7ed..4345bc8 100644
|
|
--- a/include/uapi/linux/capability.h
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|
+++ b/include/uapi/linux/capability.h
|
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@@ -364,7 +364,11 @@ struct cpu_vfs_cap_data {
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|
|
#define CAP_BLOCK_SUSPEND 36
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|
|
|
-#define CAP_LAST_CAP CAP_BLOCK_SUSPEND
|
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+/* Allow things that trivially permit root to modify the running kernel */
|
|
+
|
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+#define CAP_COMPROMISE_KERNEL 37
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+
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|
+#define CAP_LAST_CAP CAP_COMPROMISE_KERNEL
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|
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#define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)
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|
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--
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1.7.11.4
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From 95fd8148be46036e20fc64c480104d2a2b454e27 Mon Sep 17 00:00:00 2001
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From: Matthew Garrett <mjg@redhat.com>
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Date: Thu, 20 Sep 2012 10:40:57 -0400
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Subject: [PATCH 02/14] PCI: Lock down BAR access in secure boot environments
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|
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Any hardware that can potentially generate DMA has to be locked down from
|
|
userspace in order to avoid it being possible for an attacker to cause
|
|
arbitrary kernel behaviour. Default to paranoid - in future we can
|
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potentially relax this for sufficiently IOMMU-isolated devices.
|
|
|
|
Signed-off-by: Matthew Garrett <mjg@redhat.com>
|
|
---
|
|
drivers/pci/pci-sysfs.c | 9 +++++++++
|
|
drivers/pci/proc.c | 8 +++++++-
|
|
drivers/pci/syscall.c | 2 +-
|
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3 files changed, 17 insertions(+), 2 deletions(-)
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|
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diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
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index 6869009..c03fb85 100644
|
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--- a/drivers/pci/pci-sysfs.c
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+++ b/drivers/pci/pci-sysfs.c
|
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@@ -542,6 +542,9 @@ pci_write_config(struct file* filp, struct kobject *kobj,
|
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loff_t init_off = off;
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u8 *data = (u8*) buf;
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|
|
|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
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|
+
|
|
if (off > dev->cfg_size)
|
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return 0;
|
|
if (off + count > dev->cfg_size) {
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@@ -844,6 +847,9 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
|
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resource_size_t start, end;
|
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int i;
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|
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|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
|
|
+
|
|
for (i = 0; i < PCI_ROM_RESOURCE; i++)
|
|
if (res == &pdev->resource[i])
|
|
break;
|
|
@@ -951,6 +957,9 @@ pci_write_resource_io(struct file *filp, struct kobject *kobj,
|
|
struct bin_attribute *attr, char *buf,
|
|
loff_t off, size_t count)
|
|
{
|
|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
|
|
+
|
|
return pci_resource_io(filp, kobj, attr, buf, off, count, true);
|
|
}
|
|
|
|
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
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|
index 27911b5..ac8c9a5 100644
|
|
--- a/drivers/pci/proc.c
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|
+++ b/drivers/pci/proc.c
|
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@@ -135,6 +135,9 @@ proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, lof
|
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int size = dp->size;
|
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int cnt;
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|
|
|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
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+ return -EPERM;
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+
|
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if (pos >= size)
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return 0;
|
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if (nbytes >= size)
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@@ -211,6 +214,9 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
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#endif /* HAVE_PCI_MMAP */
|
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int ret = 0;
|
|
|
|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
|
|
+
|
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switch (cmd) {
|
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case PCIIOC_CONTROLLER:
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ret = pci_domain_nr(dev->bus);
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@@ -251,7 +257,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
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struct pci_filp_private *fpriv = file->private_data;
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int i, ret;
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- if (!capable(CAP_SYS_RAWIO))
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+ if (!capable(CAP_SYS_RAWIO) || !capable(CAP_COMPROMISE_KERNEL))
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return -EPERM;
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|
|
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/* Make sure the caller is mapping a real resource for this device */
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diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c
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index e1c1ec5..97e785f 100644
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--- a/drivers/pci/syscall.c
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+++ b/drivers/pci/syscall.c
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@@ -92,7 +92,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
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u32 dword;
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int err = 0;
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- if (!capable(CAP_SYS_ADMIN))
|
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+ if (!capable(CAP_SYS_ADMIN) || !capable(CAP_COMPROMISE_KERNEL))
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return -EPERM;
|
|
|
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dev = pci_get_bus_and_slot(bus, dfn);
|
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--
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1.7.11.4
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From 2d23d2726583d79062e58abcc32c7dd027d312aa Mon Sep 17 00:00:00 2001
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From: Matthew Garrett <mjg@redhat.com>
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Date: Thu, 20 Sep 2012 10:40:58 -0400
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Subject: [PATCH 03/14] x86: Lock down IO port access in secure boot
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environments
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IO port access would permit users to gain access to PCI configuration
|
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registers, which in turn (on a lot of hardware) give access to MMIO register
|
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space. This would potentially permit root to trigger arbitrary DMA, so lock
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it down by default.
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Signed-off-by: Matthew Garrett <mjg@redhat.com>
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---
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arch/x86/kernel/ioport.c | 4 ++--
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drivers/char/mem.c | 3 +++
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2 files changed, 5 insertions(+), 2 deletions(-)
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diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
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index 8c96897..a2578c4 100644
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--- a/arch/x86/kernel/ioport.c
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+++ b/arch/x86/kernel/ioport.c
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@@ -28,7 +28,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
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if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
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return -EINVAL;
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- if (turn_on && !capable(CAP_SYS_RAWIO))
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+ if (turn_on && (!capable(CAP_SYS_RAWIO) || !capable(CAP_COMPROMISE_KERNEL)))
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return -EPERM;
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/*
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@@ -102,7 +102,7 @@ long sys_iopl(unsigned int level, struct pt_regs *regs)
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return -EINVAL;
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/* Trying to gain more privileges? */
|
|
if (level > old) {
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- if (!capable(CAP_SYS_RAWIO))
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+ if (!capable(CAP_SYS_RAWIO) || !capable(CAP_COMPROMISE_KERNEL))
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return -EPERM;
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}
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regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
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diff --git a/drivers/char/mem.c b/drivers/char/mem.c
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index e5eedfa..1e0a660 100644
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--- a/drivers/char/mem.c
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+++ b/drivers/char/mem.c
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@@ -597,6 +597,9 @@ static ssize_t write_port(struct file *file, const char __user *buf,
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unsigned long i = *ppos;
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const char __user * tmp = buf;
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+ if (!capable(CAP_COMPROMISE_KERNEL))
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+ return -EPERM;
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+
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if (!access_ok(VERIFY_READ, buf, count))
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return -EFAULT;
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while (count-- > 0 && i < 65536) {
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--
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1.7.11.4
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From e063cb2f3a667d2540682d4bdbef91fdb23b1a84 Mon Sep 17 00:00:00 2001
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From: Matthew Garrett <mjg@redhat.com>
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Date: Thu, 20 Sep 2012 10:40:59 -0400
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Subject: [PATCH 04/14] ACPI: Limit access to custom_method
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It must be impossible for even root to get code executed in kernel context
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under a secure boot environment. custom_method effectively allows arbitrary
|
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access to system memory, so it needs to have a capability check here.
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Signed-off-by: Matthew Garrett <mjg@redhat.com>
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|
---
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drivers/acpi/custom_method.c | 3 +++
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1 file changed, 3 insertions(+)
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|
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diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
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index 5d42c24..247d58b 100644
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--- a/drivers/acpi/custom_method.c
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|
+++ b/drivers/acpi/custom_method.c
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|
@@ -29,6 +29,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,
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struct acpi_table_header table;
|
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acpi_status status;
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|
+ if (!capable(CAP_COMPROMISE_KERNEL))
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|
+ return -EPERM;
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+
|
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if (!(*ppos)) {
|
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/* parse the table header to get the table length */
|
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if (count <= sizeof(struct acpi_table_header))
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--
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1.7.11.4
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|
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From a1cccbd084c7355dcb2be7ae2934f168ce9ba9d5 Mon Sep 17 00:00:00 2001
|
|
From: Matthew Garrett <mjg@redhat.com>
|
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Date: Thu, 20 Sep 2012 10:41:00 -0400
|
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Subject: [PATCH 05/14] asus-wmi: Restrict debugfs interface
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|
|
|
We have no way of validating what all of the Asus WMI methods do on a
|
|
given machine, and there's a risk that some will allow hardware state to
|
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be manipulated in such a way that arbitrary code can be executed in the
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kernel. Add a capability check to prevent that.
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|
|
|
Signed-off-by: Matthew Garrett <mjg@redhat.com>
|
|
---
|
|
drivers/platform/x86/asus-wmi.c | 9 +++++++++
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|
1 file changed, 9 insertions(+)
|
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|
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diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
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|
index 2eb9fe8..61e055d 100644
|
|
--- a/drivers/platform/x86/asus-wmi.c
|
|
+++ b/drivers/platform/x86/asus-wmi.c
|
|
@@ -1523,6 +1523,9 @@ static int show_dsts(struct seq_file *m, void *data)
|
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int err;
|
|
u32 retval = -1;
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|
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+ if (!capable(CAP_COMPROMISE_KERNEL))
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+ return -EPERM;
|
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+
|
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err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval);
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|
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if (err < 0)
|
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@@ -1539,6 +1542,9 @@ static int show_devs(struct seq_file *m, void *data)
|
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int err;
|
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u32 retval = -1;
|
|
|
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+ if (!capable(CAP_COMPROMISE_KERNEL))
|
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+ return -EPERM;
|
|
+
|
|
err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param,
|
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&retval);
|
|
|
|
@@ -1563,6 +1569,9 @@ static int show_call(struct seq_file *m, void *data)
|
|
union acpi_object *obj;
|
|
acpi_status status;
|
|
|
|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
|
|
+
|
|
status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID,
|
|
1, asus->debug.method_id,
|
|
&input, &output);
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 1c9e53b626268f82509062751eda14e8572717cf Mon Sep 17 00:00:00 2001
|
|
From: Matthew Garrett <mjg@redhat.com>
|
|
Date: Thu, 20 Sep 2012 10:41:01 -0400
|
|
Subject: [PATCH 06/14] Restrict /dev/mem and /dev/kmem in secure boot setups
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|
|
Allowing users to write to address space makes it possible for the kernel
|
|
to be subverted. Restrict this when we need to protect the kernel.
|
|
|
|
Signed-off-by: Matthew Garrett <mjg@redhat.com>
|
|
---
|
|
drivers/char/mem.c | 6 ++++++
|
|
1 file changed, 6 insertions(+)
|
|
|
|
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
|
|
index 1e0a660..33eb947 100644
|
|
--- a/drivers/char/mem.c
|
|
+++ b/drivers/char/mem.c
|
|
@@ -158,6 +158,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf,
|
|
unsigned long copied;
|
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void *ptr;
|
|
|
|
+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
|
|
+
|
|
if (!valid_phys_addr_range(p, count))
|
|
return -EFAULT;
|
|
|
|
@@ -530,6 +533,9 @@ static ssize_t write_kmem(struct file *file, const char __user *buf,
|
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char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
|
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int err = 0;
|
|
|
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+ if (!capable(CAP_COMPROMISE_KERNEL))
|
|
+ return -EPERM;
|
|
+
|
|
if (p < (unsigned long) high_memory) {
|
|
unsigned long to_write = min_t(unsigned long, count,
|
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(unsigned long)high_memory - p);
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From fbf919bf372b9a7a08bdacac8129d47ced1b1f19 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Thu, 20 Sep 2012 10:41:02 -0400
|
|
Subject: [PATCH 07/14] Secure boot: Add a dummy kernel parameter that will
|
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switch on Secure Boot mode
|
|
|
|
This forcibly drops CAP_COMPROMISE_KERNEL from both cap_permitted and cap_bset
|
|
in the init_cred struct, which everything else inherits from. This works on
|
|
any machine and can be used to develop even if the box doesn't have UEFI.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
Documentation/kernel-parameters.txt | 7 +++++++
|
|
kernel/cred.c | 17 +++++++++++++++++
|
|
2 files changed, 24 insertions(+)
|
|
|
|
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
|
|
index 9b2b8d3..93978d5 100644
|
|
--- a/Documentation/kernel-parameters.txt
|
|
+++ b/Documentation/kernel-parameters.txt
|
|
@@ -2562,6 +2562,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
|
|
Note: increases power consumption, thus should only be
|
|
enabled if running jitter sensitive (HPC/RT) workloads.
|
|
|
|
+ secureboot_enable=
|
|
+ [KNL] Enables an emulated UEFI Secure Boot mode. This
|
|
+ locks down various aspects of the kernel guarded by the
|
|
+ CAP_COMPROMISE_KERNEL capability. This includes things
|
|
+ like /dev/mem, IO port access, and other areas. It can
|
|
+ be used on non-UEFI machines for testing purposes.
|
|
+
|
|
security= [SECURITY] Choose a security module to enable at boot.
|
|
If this boot parameter is not specified, only the first
|
|
security module asking for security registration will be
|
|
diff --git a/kernel/cred.c b/kernel/cred.c
|
|
index de728ac..7e6e83f 100644
|
|
--- a/kernel/cred.c
|
|
+++ b/kernel/cred.c
|
|
@@ -623,6 +623,23 @@ void __init cred_init(void)
|
|
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
|
|
}
|
|
|
|
+void __init secureboot_enable()
|
|
+{
|
|
+ pr_info("Secure boot enabled\n");
|
|
+ cap_lower((&init_cred)->cap_bset, CAP_COMPROMISE_KERNEL);
|
|
+ cap_lower((&init_cred)->cap_permitted, CAP_COMPROMISE_KERNEL);
|
|
+}
|
|
+
|
|
+/* Dummy Secure Boot enable option to fake out UEFI SB=1 */
|
|
+static int __init secureboot_enable_opt(char *str)
|
|
+{
|
|
+ int sb_enable = !!simple_strtol(str, NULL, 0);
|
|
+ if (sb_enable)
|
|
+ secureboot_enable();
|
|
+ return 1;
|
|
+}
|
|
+__setup("secureboot_enable=", secureboot_enable_opt);
|
|
+
|
|
/**
|
|
* prepare_kernel_cred - Prepare a set of credentials for a kernel service
|
|
* @daemon: A userspace daemon to be used as a reference
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 43ed7865d867ae692e30227d66fa58cdecbd9269 Mon Sep 17 00:00:00 2001
|
|
From: Matthew Garrett <mjg@redhat.com>
|
|
Date: Thu, 20 Sep 2012 10:41:03 -0400
|
|
Subject: [PATCH 08/14] efi: Enable secure boot lockdown automatically when
|
|
enabled in firmware
|
|
|
|
The firmware has a set of flags that indicate whether secure boot is enabled
|
|
and enforcing. Use them to indicate whether the kernel should lock itself
|
|
down.
|
|
|
|
Signed-off-by: Matthew Garrett <mjg@redhat.com>
|
|
---
|
|
Documentation/x86/zero-page.txt | 2 ++
|
|
arch/x86/boot/compressed/eboot.c | 32 ++++++++++++++++++++++++++++++++
|
|
arch/x86/include/asm/bootparam.h | 3 ++-
|
|
arch/x86/kernel/setup.c | 3 +++
|
|
include/linux/cred.h | 2 ++
|
|
5 files changed, 41 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
|
|
index cf5437d..7f9ed48 100644
|
|
--- a/Documentation/x86/zero-page.txt
|
|
+++ b/Documentation/x86/zero-page.txt
|
|
@@ -27,6 +27,8 @@ Offset Proto Name Meaning
|
|
1E9/001 ALL eddbuf_entries Number of entries in eddbuf (below)
|
|
1EA/001 ALL edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
|
|
(below)
|
|
+1EB/001 ALL kbd_status Numlock is enabled
|
|
+1EC/001 ALL secure_boot Kernel should enable secure boot lockdowns
|
|
290/040 ALL edd_mbr_sig_buffer EDD MBR signatures
|
|
2D0/A00 ALL e820_map E820 memory map table
|
|
(array of struct e820entry)
|
|
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
|
|
index b3e0227..3789356 100644
|
|
--- a/arch/x86/boot/compressed/eboot.c
|
|
+++ b/arch/x86/boot/compressed/eboot.c
|
|
@@ -724,6 +724,36 @@ fail:
|
|
return status;
|
|
}
|
|
|
|
+static int get_secure_boot(efi_system_table_t *_table)
|
|
+{
|
|
+ u8 sb, setup;
|
|
+ unsigned long datasize = sizeof(sb);
|
|
+ efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID;
|
|
+ efi_status_t status;
|
|
+
|
|
+ status = efi_call_phys5(sys_table->runtime->get_variable,
|
|
+ L"SecureBoot", &var_guid, NULL, &datasize, &sb);
|
|
+
|
|
+ if (status != EFI_SUCCESS)
|
|
+ return 0;
|
|
+
|
|
+ if (sb == 0)
|
|
+ return 0;
|
|
+
|
|
+
|
|
+ status = efi_call_phys5(sys_table->runtime->get_variable,
|
|
+ L"SetupMode", &var_guid, NULL, &datasize,
|
|
+ &setup);
|
|
+
|
|
+ if (status != EFI_SUCCESS)
|
|
+ return 0;
|
|
+
|
|
+ if (setup == 1)
|
|
+ return 0;
|
|
+
|
|
+ return 1;
|
|
+}
|
|
+
|
|
/*
|
|
* Because the x86 boot code expects to be passed a boot_params we
|
|
* need to create one ourselves (usually the bootloader would create
|
|
@@ -1018,6 +1048,8 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
|
|
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
|
|
goto fail;
|
|
|
|
+ boot_params->secure_boot = get_secure_boot(sys_table);
|
|
+
|
|
setup_graphics(boot_params);
|
|
|
|
status = efi_call_phys3(sys_table->boottime->allocate_pool,
|
|
diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
|
|
index 2ad874c..c7338e0 100644
|
|
--- a/arch/x86/include/asm/bootparam.h
|
|
+++ b/arch/x86/include/asm/bootparam.h
|
|
@@ -114,7 +114,8 @@ struct boot_params {
|
|
__u8 eddbuf_entries; /* 0x1e9 */
|
|
__u8 edd_mbr_sig_buf_entries; /* 0x1ea */
|
|
__u8 kbd_status; /* 0x1eb */
|
|
- __u8 _pad6[5]; /* 0x1ec */
|
|
+ __u8 secure_boot; /* 0x1ec */
|
|
+ __u8 _pad6[4]; /* 0x1ed */
|
|
struct setup_header hdr; /* setup header */ /* 0x1f1 */
|
|
__u8 _pad7[0x290-0x1f1-sizeof(struct setup_header)];
|
|
__u32 edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 0x290 */
|
|
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
|
|
index f4b9b80..239bf2a 100644
|
|
--- a/arch/x86/kernel/setup.c
|
|
+++ b/arch/x86/kernel/setup.c
|
|
@@ -947,6 +947,9 @@ void __init setup_arch(char **cmdline_p)
|
|
|
|
io_delay_init();
|
|
|
|
+ if (boot_params.secure_boot)
|
|
+ secureboot_enable();
|
|
+
|
|
/*
|
|
* Parse the ACPI tables for possible boot-time SMP configuration.
|
|
*/
|
|
diff --git a/include/linux/cred.h b/include/linux/cred.h
|
|
index ebbed2c..a24faf1 100644
|
|
--- a/include/linux/cred.h
|
|
+++ b/include/linux/cred.h
|
|
@@ -170,6 +170,8 @@ extern int set_security_override_from_ctx(struct cred *, const char *);
|
|
extern int set_create_files_as(struct cred *, struct inode *);
|
|
extern void __init cred_init(void);
|
|
|
|
+extern void secureboot_enable(void);
|
|
+
|
|
/*
|
|
* check for validity of credentials
|
|
*/
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 3acf1ceb5f6f3be9103c9da16ddc24afc6d8b02a Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Thu, 20 Sep 2012 10:41:04 -0400
|
|
Subject: [PATCH 09/14] acpi: Ignore acpi_rsdp kernel parameter in a secure
|
|
boot environment
|
|
|
|
This option allows userspace to pass the RSDP address to the kernel. This
|
|
could potentially be used to circumvent the secure boot trust model.
|
|
We ignore the setting if we don't have the CAP_COMPROMISE_KERNEL capability.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
drivers/acpi/osl.c | 2 +-
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
|
|
index 9eaf708..f94341b 100644
|
|
--- a/drivers/acpi/osl.c
|
|
+++ b/drivers/acpi/osl.c
|
|
@@ -246,7 +246,7 @@ early_param("acpi_rsdp", setup_acpi_rsdp);
|
|
acpi_physical_address __init acpi_os_get_root_pointer(void)
|
|
{
|
|
#ifdef CONFIG_KEXEC
|
|
- if (acpi_rsdp)
|
|
+ if (acpi_rsdp && capable(CAP_COMPROMISE_KERNEL))
|
|
return acpi_rsdp;
|
|
#endif
|
|
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 03fb06d272ddc1062e610521c5cfdbe42f251209 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Thu, 20 Sep 2012 10:41:05 -0400
|
|
Subject: [PATCH 10/14] SELinux: define mapping for new Secure Boot capability
|
|
|
|
Add the name of the new Secure Boot capability. This allows SELinux
|
|
policies to properly map CAP_COMPROMISE_KERNEL to the appropriate
|
|
capability class.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
security/selinux/include/classmap.h | 4 ++--
|
|
1 file changed, 2 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
|
|
index df2de54..70e2834 100644
|
|
--- a/security/selinux/include/classmap.h
|
|
+++ b/security/selinux/include/classmap.h
|
|
@@ -146,8 +146,8 @@ struct security_class_mapping secclass_map[] = {
|
|
{ "memprotect", { "mmap_zero", NULL } },
|
|
{ "peer", { "recv", NULL } },
|
|
{ "capability2",
|
|
- { "mac_override", "mac_admin", "syslog", "wake_alarm", "block_suspend",
|
|
- NULL } },
|
|
+ { "mac_override", "mac_admin", "syslog", "wake_alarm",
|
|
+ "block_suspend", "compromise_kernel", NULL } },
|
|
{ "kernel_service", { "use_as_override", "create_files_as", NULL } },
|
|
{ "tun_socket",
|
|
{ COMMON_SOCK_PERMS, NULL } },
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 0cfaa5ecf01f8eaaa2a84d88b7258a94ac9a1bfe Mon Sep 17 00:00:00 2001
|
|
From: Matthew Garrett <mjg@redhat.com>
|
|
Date: Tue, 4 Sep 2012 11:55:13 -0400
|
|
Subject: [PATCH 11/14] kexec: Disable in a secure boot environment
|
|
|
|
kexec could be used as a vector for a malicious user to use a signed kernel
|
|
to circumvent the secure boot trust model. In the long run we'll want to
|
|
support signed kexec payloads, but for the moment we should just disable
|
|
loading entirely in that situation.
|
|
|
|
Signed-off-by: Matthew Garrett <mjg@redhat.com>
|
|
---
|
|
kernel/kexec.c | 2 +-
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
diff --git a/kernel/kexec.c b/kernel/kexec.c
|
|
index 0668d58..8b976a5 100644
|
|
--- a/kernel/kexec.c
|
|
+++ b/kernel/kexec.c
|
|
@@ -944,7 +944,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
|
|
int result;
|
|
|
|
/* We only trust the superuser with rebooting the system. */
|
|
- if (!capable(CAP_SYS_BOOT))
|
|
+ if (!capable(CAP_SYS_BOOT) || !capable(CAP_COMPROMISE_KERNEL))
|
|
return -EPERM;
|
|
|
|
/*
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 895c46276788b3711aee05a1a1d685eff69d48b9 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Mon, 25 Jun 2012 21:29:46 -0400
|
|
Subject: [PATCH 12/14] Documentation: kernel-parameters.txt remove
|
|
capability.disable
|
|
|
|
Remove the documentation for capability.disable. The code supporting this
|
|
parameter was removed with:
|
|
|
|
commit 5915eb53861c5776cfec33ca4fcc1fd20d66dd27
|
|
Author: Miklos Szeredi <mszeredi@suse.cz>
|
|
Date: Thu Jul 3 20:56:05 2008 +0200
|
|
|
|
security: remove dummy module
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
Documentation/kernel-parameters.txt | 6 ------
|
|
1 file changed, 6 deletions(-)
|
|
|
|
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
|
|
index 93978d5..e3e5f8c 100644
|
|
--- a/Documentation/kernel-parameters.txt
|
|
+++ b/Documentation/kernel-parameters.txt
|
|
@@ -446,12 +446,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
|
|
possible to determine what the correct size should be.
|
|
This option provides an override for these situations.
|
|
|
|
- capability.disable=
|
|
- [SECURITY] Disable capabilities. This would normally
|
|
- be used only if an alternative security model is to be
|
|
- configured. Potentially dangerous and should only be
|
|
- used if you are entirely sure of the consequences.
|
|
-
|
|
ccw_timeout_log [S390]
|
|
See Documentation/s390/CommonIO for details.
|
|
|
|
--
|
|
1.7.11.4
|
|
|
|
|
|
From 1cc529e97756554953187fe48b9b8cf0e24b9bc7 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Fri, 5 Oct 2012 10:12:48 -0400
|
|
Subject: [PATCH] modsign: Always enforce module signing in a Secure Boot
|
|
environment
|
|
|
|
If a machine is booted into a Secure Boot environment, we need to
|
|
protect the trust model. This requires that all modules be signed
|
|
with a key that is in the kernel's _modsign keyring. The checks for
|
|
this are already done via the 'sig_enforce' module parameter. Make
|
|
this visible within the kernel and force it to be true.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
kernel/cred.c | 8 ++++++++
|
|
kernel/module.c | 4 ++--
|
|
2 files changed, 10 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/kernel/cred.c b/kernel/cred.c
|
|
index 7e6e83f..2b0b980 100644
|
|
--- a/kernel/cred.c
|
|
+++ b/kernel/cred.c
|
|
@@ -623,11 +623,19 @@ void __init cred_init(void)
|
|
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
|
|
}
|
|
|
|
+#ifdef CONFIG_MODULE_SIG
|
|
+extern bool sig_enforce;
|
|
+#endif
|
|
+
|
|
void __init secureboot_enable()
|
|
{
|
|
pr_info("Secure boot enabled\n");
|
|
cap_lower((&init_cred)->cap_bset, CAP_COMPROMISE_KERNEL);
|
|
cap_lower((&init_cred)->cap_permitted, CAP_COMPROMISE_KERNEL);
|
|
+#ifdef CONFIG_MODULE_SIG
|
|
+ /* Enable module signature enforcing */
|
|
+ sig_enforce = true;
|
|
+#endif
|
|
}
|
|
|
|
/* Dummy Secure Boot enable option to fake out UEFI SB=1 */
|
|
diff --git a/kernel/module.c b/kernel/module.c
|
|
index de16959..7d4c50a 100644
|
|
--- a/kernel/module.c
|
|
+++ b/kernel/module.c
|
|
@@ -106,9 +106,9 @@ struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
|
|
|
|
#ifdef CONFIG_MODULE_SIG
|
|
#ifdef CONFIG_MODULE_SIG_FORCE
|
|
-static bool sig_enforce = true;
|
|
+bool sig_enforce = true;
|
|
#else
|
|
-static bool sig_enforce = false;
|
|
+bool sig_enforce = false;
|
|
|
|
static int param_set_bool_enable_only(const char *val,
|
|
const struct kernel_param *kp)
|
|
--
|
|
1.7.11.4
|
|
|
|
From 945f3829d0d376c5e0c790b57c4fa9e875d602d3 Mon Sep 17 00:00:00 2001
|
|
From: Dave Howells <dhowells@redhat.com>
|
|
Date: Tue, 23 Oct 2012 09:30:54 -0400
|
|
Subject: [PATCH 1/2] Add EFI signature data types, such as are used for
|
|
containing hashes, keys and certificates for
|
|
cryptographic verification.
|
|
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
---
|
|
include/linux/efi.h | 20 ++++++++++++++++++++
|
|
1 file changed, 20 insertions(+)
|
|
|
|
diff --git a/include/linux/efi.h b/include/linux/efi.h
|
|
index 8670eb1..836c797 100644
|
|
--- a/include/linux/efi.h
|
|
+++ b/include/linux/efi.h
|
|
@@ -312,6 +312,12 @@ typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
|
|
#define EFI_FILE_SYSTEM_GUID \
|
|
EFI_GUID( 0x964e5b22, 0x6459, 0x11d2, 0x8e, 0x39, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b )
|
|
|
|
+#define EFI_CERT_SHA256_GUID \
|
|
+ EFI_GUID( 0xc1c41626, 0x504c, 0x4092, 0xac, 0xa9, 0x41, 0xf9, 0x36, 0x93, 0x43, 0x28 )
|
|
+
|
|
+#define EFI_CERT_X509_GUID \
|
|
+ EFI_GUID( 0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72 )
|
|
+
|
|
typedef struct {
|
|
efi_guid_t guid;
|
|
u64 table;
|
|
@@ -447,6 +453,20 @@ typedef struct {
|
|
|
|
#define EFI_INVALID_TABLE_ADDR (~0UL)
|
|
|
|
+typedef struct {
|
|
+ efi_guid_t signature_owner;
|
|
+ u8 signature_data[];
|
|
+} efi_signature_data_t;
|
|
+
|
|
+typedef struct {
|
|
+ efi_guid_t signature_type;
|
|
+ u32 signature_list_size;
|
|
+ u32 signature_header_size;
|
|
+ u32 signature_size;
|
|
+ u8 signature_header[];
|
|
+ /* efi_signature_data_t signatures[][] */
|
|
+} efi_signature_list_t;
|
|
+
|
|
/*
|
|
* All runtime access to EFI goes through this structure:
|
|
*/
|
|
--
|
|
1.7.12.1
|
|
|
|
|
|
From 5934634101936bc4ee4636df7269e00c4979911c Mon Sep 17 00:00:00 2001
|
|
From: Dave Howells <dhowells@redhat.com>
|
|
Date: Tue, 23 Oct 2012 09:36:28 -0400
|
|
Subject: [PATCH 2/2] Add an EFI signature blob parser and key loader. X.509
|
|
certificates are loaded into the specified keyring as
|
|
asymmetric type keys.
|
|
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
|
|
---
|
|
crypto/asymmetric_keys/Kconfig | 7 +++
|
|
crypto/asymmetric_keys/Makefile | 1 +
|
|
crypto/asymmetric_keys/efi_parser.c | 107 ++++++++++++++++++++++++++++++++++++
|
|
include/linux/efi.h | 4 ++
|
|
4 files changed, 119 insertions(+)
|
|
create mode 100644 crypto/asymmetric_keys/efi_parser.c
|
|
|
|
diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
|
|
index 6d2c2ea..eb53fc3 100644
|
|
--- a/crypto/asymmetric_keys/Kconfig
|
|
+++ b/crypto/asymmetric_keys/Kconfig
|
|
@@ -35,4 +35,11 @@ config X509_CERTIFICATE_PARSER
|
|
data and provides the ability to instantiate a crypto key from a
|
|
public key packet found inside the certificate.
|
|
|
|
+config EFI_SIGNATURE_LIST_PARSER
|
|
+ bool "EFI signature list parser"
|
|
+ select X509_CERTIFICATE_PARSER
|
|
+ help
|
|
+ This option provides support for parsing EFI signature lists for
|
|
+ X.509 certificates and turning them into keys.
|
|
+
|
|
endif # ASYMMETRIC_KEY_TYPE
|
|
diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
|
|
index 0727204..cd8388e 100644
|
|
--- a/crypto/asymmetric_keys/Makefile
|
|
+++ b/crypto/asymmetric_keys/Makefile
|
|
@@ -8,6 +8,7 @@ asymmetric_keys-y := asymmetric_type.o signature.o
|
|
|
|
obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
|
|
obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa.o
|
|
+obj-$(CONFIG_EFI_SIGNATURE_LIST_PARSER) += efi_parser.o
|
|
|
|
#
|
|
# X.509 Certificate handling
|
|
diff --git a/crypto/asymmetric_keys/efi_parser.c b/crypto/asymmetric_keys/efi_parser.c
|
|
new file mode 100644
|
|
index 0000000..59b859a
|
|
--- /dev/null
|
|
+++ b/crypto/asymmetric_keys/efi_parser.c
|
|
@@ -0,0 +1,107 @@
|
|
+/* EFI signature/key/certificate list parser
|
|
+ *
|
|
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
|
|
+ * Written by David Howells (dhowells@redhat.com)
|
|
+ *
|
|
+ * This program is free software; you can redistribute it and/or
|
|
+ * modify it under the terms of the GNU General Public Licence
|
|
+ * as published by the Free Software Foundation; either version
|
|
+ * 2 of the Licence, or (at your option) any later version.
|
|
+ */
|
|
+
|
|
+#define pr_fmt(fmt) "EFI: "fmt
|
|
+#include <linux/module.h>
|
|
+#include <linux/printk.h>
|
|
+#include <linux/err.h>
|
|
+#include <linux/efi.h>
|
|
+#include <keys/asymmetric-type.h>
|
|
+
|
|
+static __initdata efi_guid_t efi_cert_x509_guid = EFI_CERT_X509_GUID;
|
|
+
|
|
+/**
|
|
+ * parse_efi_signature_list - Parse an EFI signature list for certificates
|
|
+ * @data: The data blob to parse
|
|
+ * @size: The size of the data blob
|
|
+ * @keyring: The keyring to add extracted keys to
|
|
+ */
|
|
+int __init parse_efi_signature_list(const void *data, size_t size, struct key *keyring)
|
|
+{
|
|
+ unsigned offs = 0;
|
|
+ size_t lsize, esize, hsize, elsize;
|
|
+
|
|
+ pr_devel("-->%s(,%zu)\n", __func__, size);
|
|
+
|
|
+ while (size > 0) {
|
|
+ efi_signature_list_t list;
|
|
+ const efi_signature_data_t *elem;
|
|
+ key_ref_t key;
|
|
+
|
|
+ if (size < sizeof(list))
|
|
+ return -EBADMSG;
|
|
+
|
|
+ memcpy(&list, data, sizeof(list));
|
|
+ pr_devel("LIST[%04x] guid=%pUl ls=%x hs=%x ss=%x\n",
|
|
+ offs,
|
|
+ list.signature_type.b, list.signature_list_size,
|
|
+ list.signature_header_size, list.signature_size);
|
|
+
|
|
+ lsize = list.signature_list_size;
|
|
+ hsize = list.signature_header_size;
|
|
+ esize = list.signature_size;
|
|
+ elsize = lsize - sizeof(list) - hsize;
|
|
+
|
|
+ if (lsize > size) {
|
|
+ pr_devel("<--%s() = -EBADMSG [overrun @%x]\n",
|
|
+ __func__, offs);
|
|
+ return -EBADMSG;
|
|
+ }
|
|
+ if (lsize < sizeof(list) ||
|
|
+ lsize - sizeof(list) < hsize ||
|
|
+ esize < sizeof(*elem) ||
|
|
+ elsize < esize ||
|
|
+ elsize % esize != 0) {
|
|
+ pr_devel("- bad size combo @%x\n", offs);
|
|
+ continue;
|
|
+ }
|
|
+
|
|
+ if (efi_guidcmp(list.signature_type, efi_cert_x509_guid) != 0) {
|
|
+ data += lsize;
|
|
+ size -= lsize;
|
|
+ offs += lsize;
|
|
+ continue;
|
|
+ }
|
|
+
|
|
+ data += sizeof(list) + hsize;
|
|
+ size -= sizeof(list) + hsize;
|
|
+ offs += sizeof(list) + hsize;
|
|
+
|
|
+ for (; elsize > 0; elsize -= esize) {
|
|
+ elem = data;
|
|
+
|
|
+ pr_devel("ELEM[%04x]\n", offs);
|
|
+
|
|
+ key = key_create_or_update(
|
|
+ make_key_ref(keyring, 1),
|
|
+ "asymmetric",
|
|
+ NULL,
|
|
+ &elem->signature_data,
|
|
+ esize - sizeof(*elem),
|
|
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) |
|
|
+ KEY_USR_VIEW,
|
|
+ KEY_ALLOC_NOT_IN_QUOTA);
|
|
+
|
|
+ if (IS_ERR(key))
|
|
+ pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
|
|
+ PTR_ERR(key));
|
|
+ else
|
|
+ pr_notice("Loaded cert '%s'\n",
|
|
+ key_ref_to_ptr(key)->description);
|
|
+
|
|
+ data += esize;
|
|
+ size -= esize;
|
|
+ offs += esize;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ return 0;
|
|
+}
|
|
diff --git a/include/linux/efi.h b/include/linux/efi.h
|
|
index 836c797..9cc3250 100644
|
|
--- a/include/linux/efi.h
|
|
+++ b/include/linux/efi.h
|
|
@@ -536,6 +536,10 @@ extern int efi_set_rtc_mmss(unsigned long nowtime);
|
|
extern void efi_reserve_boot_services(void);
|
|
extern struct efi_memory_map memmap;
|
|
|
|
+struct key;
|
|
+extern int __init parse_efi_signature_list(const void *data, size_t size,
|
|
+ struct key *keyring);
|
|
+
|
|
/**
|
|
* efi_range_is_wc - check the WC bit on an address range
|
|
* @start: starting kvirt address
|
|
--
|
|
1.7.12.1
|
|
|
|
From 84d11d541cc039e8561d06deab5f9b700f12f246 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Fri, 26 Oct 2012 12:29:49 -0400
|
|
Subject: [PATCH 1/3] EFI: Add in-kernel variable to determine if Secure Boot
|
|
is enabled
|
|
|
|
There are a few cases where in-kernel functions may need to know if
|
|
Secure Boot is enabled. The added capability check cannot be used as the
|
|
kernel can't drop it's own capabilites, so we add a global variable
|
|
similar to efi_enabled so they can determine if Secure Boot is enabled.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
arch/x86/kernel/setup.c | 4 +++-
|
|
arch/x86/platform/efi/efi.c | 2 ++
|
|
include/linux/efi.h | 3 +++
|
|
3 files changed, 8 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
|
|
index 51f6970..d5b9548 100644
|
|
--- a/arch/x86/kernel/setup.c
|
|
+++ b/arch/x86/kernel/setup.c
|
|
@@ -961,8 +961,10 @@ void __init setup_arch(char **cmdline_p)
|
|
|
|
io_delay_init();
|
|
|
|
- if (boot_params.secure_boot)
|
|
+ if (boot_params.secure_boot) {
|
|
secureboot_enable();
|
|
+ secure_boot_enabled = 1;
|
|
+ }
|
|
|
|
/*
|
|
* Parse the ACPI tables for possible boot-time SMP configuration.
|
|
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
|
|
index aded2a9..e57320b 100644
|
|
--- a/arch/x86/platform/efi/efi.c
|
|
+++ b/arch/x86/platform/efi/efi.c
|
|
@@ -54,6 +54,8 @@
|
|
int efi_enabled;
|
|
EXPORT_SYMBOL(efi_enabled);
|
|
|
|
+int secure_boot_enabled;
|
|
+
|
|
struct efi __read_mostly efi = {
|
|
.mps = EFI_INVALID_TABLE_ADDR,
|
|
.acpi = EFI_INVALID_TABLE_ADDR,
|
|
diff --git a/include/linux/efi.h b/include/linux/efi.h
|
|
index 9cc3250..ff72468 100644
|
|
--- a/include/linux/efi.h
|
|
+++ b/include/linux/efi.h
|
|
@@ -573,11 +573,14 @@ extern int __init efi_setup_pcdp_console(char *);
|
|
# ifdef CONFIG_X86
|
|
extern int efi_enabled;
|
|
extern bool efi_64bit;
|
|
+ extern int secure_boot_enabled;
|
|
# else
|
|
# define efi_enabled 1
|
|
+# define secure_boot_enabled 0
|
|
# endif
|
|
#else
|
|
# define efi_enabled 0
|
|
+# define secure_boot_enabled 0
|
|
#endif
|
|
|
|
/*
|
|
--
|
|
1.7.12.1
|
|
|
|
|
|
From 2a5f33b264daffd717b509bc5ac3cdc060b5573e Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Fri, 26 Oct 2012 12:36:24 -0400
|
|
Subject: [PATCH 2/3] MODSIGN: Add module certificate blacklist keyring
|
|
|
|
This adds an additional keyring that is used to store certificates that
|
|
are blacklisted. This keyring is searched first when loading signed modules
|
|
and if the module's certificate is found, it will refuse to load. This is
|
|
useful in cases where third party certificates are used for module signing.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
init/Kconfig | 8 ++++++++
|
|
kernel/modsign_pubkey.c | 17 +++++++++++++++++
|
|
kernel/module-internal.h | 3 +++
|
|
kernel/module_signing.c | 14 +++++++++++++-
|
|
4 files changed, 41 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/init/Kconfig b/init/Kconfig
|
|
index 6fdd6e3..7a9bf00 100644
|
|
--- a/init/Kconfig
|
|
+++ b/init/Kconfig
|
|
@@ -1602,6 +1602,14 @@ config MODULE_SIG_FORCE
|
|
Reject unsigned modules or signed modules for which we don't have a
|
|
key. Without this, such modules will simply taint the kernel.
|
|
|
|
+config MODULE_SIG_BLACKLIST
|
|
+ bool "Support for blacklisting module signature certificates"
|
|
+ depends on MODULE_SIG
|
|
+ help
|
|
+ This adds support for keeping a blacklist of certificates that
|
|
+ should not pass module signature verification. If a module is
|
|
+ signed with something in this keyring, the load will be rejected.
|
|
+
|
|
choice
|
|
prompt "Which hash algorithm should modules be signed with?"
|
|
depends on MODULE_SIG
|
|
diff --git a/kernel/modsign_pubkey.c b/kernel/modsign_pubkey.c
|
|
index 4646eb2..6d70783 100644
|
|
--- a/kernel/modsign_pubkey.c
|
|
+++ b/kernel/modsign_pubkey.c
|
|
@@ -17,6 +17,9 @@
|
|
#include "module-internal.h"
|
|
|
|
struct key *modsign_keyring;
|
|
+#ifdef CONFIG_MODULE_SIG_BLACKLIST
|
|
+struct key *modsign_blacklist;
|
|
+#endif
|
|
|
|
extern __initdata const u8 modsign_certificate_list[];
|
|
extern __initdata const u8 modsign_certificate_list_end[];
|
|
@@ -52,6 +55,20 @@ static __init int module_verify_init(void)
|
|
if (key_instantiate_and_link(modsign_keyring, NULL, 0, NULL, NULL) < 0)
|
|
panic("Can't instantiate module signing keyring\n");
|
|
|
|
+#ifdef CONFIG_MODULE_SIG_BLACKLIST
|
|
+ modsign_blacklist = key_alloc(&key_type_keyring, ".modsign_blacklist",
|
|
+ KUIDT_INIT(0), KGIDT_INIT(0),
|
|
+ current_cred(),
|
|
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) |
|
|
+ KEY_USR_VIEW | KEY_USR_READ,
|
|
+ KEY_ALLOC_NOT_IN_QUOTA);
|
|
+ if (IS_ERR(modsign_blacklist))
|
|
+ panic("Can't allocate module signing blacklist keyring\n");
|
|
+
|
|
+ if (key_instantiate_and_link(modsign_blacklist, NULL, 0, NULL, NULL) < 0)
|
|
+ panic("Can't instantiate module signing blacklist keyring\n");
|
|
+#endif
|
|
+
|
|
return 0;
|
|
}
|
|
|
|
diff --git a/kernel/module-internal.h b/kernel/module-internal.h
|
|
index 24f9247..51a8380 100644
|
|
--- a/kernel/module-internal.h
|
|
+++ b/kernel/module-internal.h
|
|
@@ -10,5 +10,8 @@
|
|
*/
|
|
|
|
extern struct key *modsign_keyring;
|
|
+#ifdef CONFIG_MODULE_SIG_BLACKLIST
|
|
+extern struct key *modsign_blacklist;
|
|
+#endif
|
|
|
|
extern int mod_verify_sig(const void *mod, unsigned long *_modlen);
|
|
diff --git a/kernel/module_signing.c b/kernel/module_signing.c
|
|
index ea1b1df..602aa24 100644
|
|
--- a/kernel/module_signing.c
|
|
+++ b/kernel/module_signing.c
|
|
@@ -132,7 +132,7 @@ static int mod_extract_mpi_array(struct public_key_signature *pks,
|
|
static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
|
|
const u8 *key_id, size_t key_id_len)
|
|
{
|
|
- key_ref_t key;
|
|
+ key_ref_t key, blacklist;
|
|
size_t i;
|
|
char *id, *q;
|
|
|
|
@@ -157,6 +157,18 @@ static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
|
|
|
|
pr_debug("Look up: \"%s\"\n", id);
|
|
|
|
+#ifdef CONFIG_MODULE_SIG_BLACKLIST
|
|
+ blacklist = keyring_search(make_key_ref(modsign_blacklist, 1),
|
|
+ &key_type_asymmetric, id);
|
|
+ if (!IS_ERR(blacklist)) {
|
|
+ /* module is signed with a cert in the blacklist. reject */
|
|
+ pr_err("Module key '%s' is in blacklist\n", id);
|
|
+ key_ref_put(blacklist);
|
|
+ kfree(id);
|
|
+ return ERR_PTR(-EKEYREJECTED);
|
|
+ }
|
|
+#endif
|
|
+
|
|
key = keyring_search(make_key_ref(modsign_keyring, 1),
|
|
&key_type_asymmetric, id);
|
|
if (IS_ERR(key))
|
|
--
|
|
1.7.12.1
|
|
|
|
|
|
|
|
From ddd5e2e1b775fb19aeec7fb842e707fc35347bc0 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Fri, 26 Oct 2012 12:42:16 -0400
|
|
Subject: [PATCH] MODSIGN: Import certificates from UEFI Secure Boot
|
|
|
|
Secure Boot stores a list of allowed certificates in the 'db' variable.
|
|
This imports those certificates into the module signing keyring. This
|
|
allows for a third party signing certificate to be used in conjunction
|
|
with signed modules. By importing the public certificate into the 'db'
|
|
variable, a user can allow a module signed with that certificate to
|
|
load.
|
|
|
|
In the opposite case, Secure Boot maintains a list of disallowed
|
|
certificates in the 'dbx' variable. We load those certificates into
|
|
the newly introduced module blacklist keyring and forbid any module
|
|
signed with those from loading.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
include/linux/efi.h | 3 ++
|
|
init/Kconfig | 9 ++++++
|
|
kernel/Makefile | 3 ++
|
|
kernel/modsign_uefi.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
4 files changed, 99 insertions(+)
|
|
create mode 100644 kernel/modsign_uefi.c
|
|
|
|
diff --git a/include/linux/efi.h b/include/linux/efi.h
|
|
index ff72468..509755e 100644
|
|
--- a/include/linux/efi.h
|
|
+++ b/include/linux/efi.h
|
|
@@ -318,6 +318,9 @@ typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
|
|
#define EFI_CERT_X509_GUID \
|
|
EFI_GUID( 0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72 )
|
|
|
|
+#define EFI_IMAGE_SECURITY_DATABASE_GUID \
|
|
+ EFI_GUID( 0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f )
|
|
+
|
|
typedef struct {
|
|
efi_guid_t guid;
|
|
u64 table;
|
|
diff --git a/init/Kconfig b/init/Kconfig
|
|
index 7a9bf00..9c4c529 100644
|
|
--- a/init/Kconfig
|
|
+++ b/init/Kconfig
|
|
@@ -1610,6 +1610,15 @@ config MODULE_SIG_BLACKLIST
|
|
should not pass module signature verification. If a module is
|
|
signed with something in this keyring, the load will be rejected.
|
|
|
|
+config MODULE_SIG_UEFI
|
|
+ bool "Allow modules signed with certs stored in UEFI"
|
|
+ depends on MODULE_SIG && MODULE_SIG_BLACKLIST && EFI
|
|
+ select EFI_SIGNATURE_LIST_PARSER
|
|
+ help
|
|
+ This will import certificates stored in UEFI and allow modules
|
|
+ signed with those to be loaded. It will also disallow loading
|
|
+ of modules stored in the UEFI dbx variable.
|
|
+
|
|
choice
|
|
prompt "Which hash algorithm should modules be signed with?"
|
|
depends on MODULE_SIG
|
|
diff --git a/kernel/Makefile b/kernel/Makefile
|
|
index 0dfeca4..ff1468f 100644
|
|
--- a/kernel/Makefile
|
|
+++ b/kernel/Makefile
|
|
@@ -55,6 +55,7 @@ obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
|
|
obj-$(CONFIG_UID16) += uid16.o
|
|
obj-$(CONFIG_MODULES) += module.o
|
|
obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o
|
|
+obj-$(CONFIG_MODULE_SIG_UEFI) += modsign_uefi.o
|
|
obj-$(CONFIG_KALLSYMS) += kallsyms.o
|
|
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
|
|
obj-$(CONFIG_KEXEC) += kexec.o
|
|
@@ -113,6 +114,8 @@ obj-$(CONFIG_JUMP_LABEL) += jump_label.o
|
|
|
|
$(obj)/configs.o: $(obj)/config_data.h
|
|
|
|
+$(obj)/modsign_uefi.o: KBUILD_CFLAGS += -fshort-wchar
|
|
+
|
|
# config_data.h contains the same information as ikconfig.h but gzipped.
|
|
# Info from config_data can be extracted from /proc/config*
|
|
targets += config_data.gz
|
|
diff --git a/kernel/modsign_uefi.c b/kernel/modsign_uefi.c
|
|
new file mode 100644
|
|
index 0000000..049669d
|
|
--- /dev/null
|
|
+++ b/kernel/modsign_uefi.c
|
|
@@ -0,0 +1,84 @@
|
|
+#include <linux/kernel.h>
|
|
+#include <linux/sched.h>
|
|
+#include <linux/cred.h>
|
|
+#include <linux/err.h>
|
|
+#include <linux/efi.h>
|
|
+#include <keys/asymmetric-type.h>
|
|
+#include "module-internal.h"
|
|
+
|
|
+static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, unsigned long *size)
|
|
+{
|
|
+ efi_status_t status;
|
|
+ unsigned long lsize = 4;
|
|
+ unsigned long tmpdb[4];
|
|
+ void *db = NULL;
|
|
+
|
|
+ status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
|
|
+ if (status != EFI_BUFFER_TOO_SMALL) {
|
|
+ pr_err("Couldn't get size: 0x%lx\n", status);
|
|
+ return NULL;
|
|
+ }
|
|
+
|
|
+ db = kmalloc(lsize, GFP_KERNEL);
|
|
+ if (!db) {
|
|
+ pr_err("Couldn't allocate memory for uefi cert list\n");
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ status = efi.get_variable(name, guid, NULL, &lsize, db);
|
|
+ if (status != EFI_SUCCESS) {
|
|
+ kfree(db);
|
|
+ db = NULL;
|
|
+ pr_err("Error reading db var: 0x%lx\n", status);
|
|
+ }
|
|
+out:
|
|
+ *size = lsize;
|
|
+ return db;
|
|
+}
|
|
+
|
|
+/*
|
|
+ * * Load the certs contained in the UEFI databases
|
|
+ * */
|
|
+static int __init load_uefi_certs(void)
|
|
+{
|
|
+ efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID;
|
|
+ void *db = NULL, *dbx = NULL;
|
|
+ unsigned long dbsize = 0, dbxsize = 0;
|
|
+ int rc = 0;
|
|
+
|
|
+ /* Check if SB is enabled and just return if not */
|
|
+ if (!secure_boot_enabled)
|
|
+ return 0;
|
|
+
|
|
+ db = get_cert_list(L"db", &secure_var, &dbsize);
|
|
+ if (!db) {
|
|
+ pr_err("Couldn't get db list\n");
|
|
+ rc = -1;
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ /* Get dbx. It might not exist, so it isn't an error if we can't
|
|
+ * get it.
|
|
+ */
|
|
+ dbx = get_cert_list(L"dbx", &secure_var, &dbxsize);
|
|
+ if (!dbx) {
|
|
+ pr_err("Couldn't get dbx list\n");
|
|
+ }
|
|
+
|
|
+ rc = parse_efi_signature_list(db, dbsize, modsign_keyring);
|
|
+ if (rc)
|
|
+ pr_err("Couldn't parse db signatures: %d\n", rc);
|
|
+
|
|
+ if (dbx) {
|
|
+ rc = parse_efi_signature_list(dbx, dbxsize,
|
|
+ modsign_blacklist);
|
|
+ if (rc)
|
|
+ pr_err("Couldn't parse dbx signatures: %d\n", rc);
|
|
+ }
|
|
+
|
|
+err:
|
|
+ kfree(db);
|
|
+ kfree(dbx);
|
|
+ return rc;
|
|
+}
|
|
+late_initcall(load_uefi_certs);
|
|
--
|
|
1.7.12.1
|
|
|
|
From d037dc552a62b1dd39b457e10c133a4509b0efc3 Mon Sep 17 00:00:00 2001
|
|
From: Josh Boyer <jwboyer@redhat.com>
|
|
Date: Fri, 26 Oct 2012 14:02:09 -0400
|
|
Subject: [PATCH] hibernate: Disable in a Secure Boot environment
|
|
|
|
There is currently no way to verify the resume image when returning
|
|
from hibernate. This might compromise the secure boot trust model,
|
|
so until we can work with signed hibernate images we disable it in
|
|
a Secure Boot environment.
|
|
|
|
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
|
|
---
|
|
kernel/power/hibernate.c | 14 +++++++++++++-
|
|
kernel/power/main.c | 4 +++-
|
|
2 files changed, 16 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
|
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index b26f5f1..f04343b 100644
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--- a/kernel/power/hibernate.c
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+++ b/kernel/power/hibernate.c
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@@ -632,6 +632,10 @@ int hibernate(void)
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{
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int error;
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+ if (!capable(CAP_COMPROMISE_KERNEL)) {
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+ return -EPERM;
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+ }
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+
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lock_system_sleep();
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/* The snapshot device should not be opened while we're running */
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if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
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@@ -723,7 +727,7 @@ static int software_resume(void)
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/*
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* If the user said "noresume".. bail out early.
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*/
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- if (noresume)
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+ if (noresume || !capable(CAP_COMPROMISE_KERNEL))
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return 0;
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/*
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@@ -889,6 +893,11 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
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int i;
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char *start = buf;
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+ if (!capable(CAP_COMPROMISE_KERNEL)) {
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+ buf += sprintf(buf, "[%s]\n", "disabled");
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+ return buf-start;
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+ }
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+
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for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
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if (!hibernation_modes[i])
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continue;
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@@ -923,6 +932,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
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char *p;
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int mode = HIBERNATION_INVALID;
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+ if (!capable(CAP_COMPROMISE_KERNEL))
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+ return -EPERM;
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+
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p = memchr(buf, '\n', n);
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len = p ? p - buf : n;
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diff --git a/kernel/power/main.c b/kernel/power/main.c
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index f458238..72580c1 100644
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--- a/kernel/power/main.c
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+++ b/kernel/power/main.c
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@@ -301,7 +301,9 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
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}
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#endif
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#ifdef CONFIG_HIBERNATION
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- s += sprintf(s, "%s\n", "disk");
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+ if (capable(CAP_COMPROMISE_KERNEL)) {
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+ s += sprintf(s, "%s\n", "disk");
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+ }
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#else
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if (s != buf)
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/* convert the last space to a newline */
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--
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1.7.12.1
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