From 617309bdd75bbce794ae2d41d44e7b76fb8c6d8b Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Thu, 8 Mar 2012 09:56:33 -0500
Subject: [PATCH 01/13] 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
capability set if required.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
include/linux/capability.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/capability.h b/include/linux/capability.h
index d10b7ed..6a39163 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -364,7 +364,11 @@ struct cpu_vfs_cap_data {
#define CAP_BLOCK_SUSPEND 36
-#define CAP_LAST_CAP CAP_BLOCK_SUSPEND
+/* Allow things that are dangerous under secure boot */
+
+#define CAP_SECURE_FIRMWARE 37
+
+#define CAP_LAST_CAP CAP_SECURE_FIRMWARE
#define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)
--
1.7.11.2
From ac892cb2320872717005736c8ef88208c12e61ee Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Thu, 8 Mar 2012 10:10:38 -0500
Subject: [PATCH 02/13] PCI: Lock down BAR access in secure boot environments
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
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 +-
3 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 6869009..a1ad0f7 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -542,6 +542,9 @@ pci_write_config(struct file* filp, struct kobject *kobj,
loff_t init_off = off;
u8 *data = (u8*) buf;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
if (off > dev->cfg_size)
return 0;
if (off + count > dev->cfg_size) {
@@ -844,6 +847,9 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
resource_size_t start, end;
int i;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ 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_SECURE_FIRMWARE))
+ 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
index 27911b5..01d4753 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -135,6 +135,9 @@ proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, lof
int size = dp->size;
int cnt;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
if (pos >= size)
return 0;
if (nbytes >= size)
@@ -211,6 +214,9 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
#endif /* HAVE_PCI_MMAP */
int ret = 0;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
switch (cmd) {
case PCIIOC_CONTROLLER:
ret = pci_domain_nr(dev->bus);
@@ -251,7 +257,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)
struct pci_filp_private *fpriv = file->private_data;
int i, ret;
- if (!capable(CAP_SYS_RAWIO))
+ if (!capable(CAP_SYS_RAWIO) || !capable(CAP_SECURE_FIRMWARE))
return -EPERM;
/* Make sure the caller is mapping a real resource for this device */
diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c
index e1c1ec5..a778ba9 100644
--- a/drivers/pci/syscall.c
+++ b/drivers/pci/syscall.c
@@ -92,7 +92,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
u32 dword;
int err = 0;
- if (!capable(CAP_SYS_ADMIN))
+ if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SECURE_FIRMWARE))
return -EPERM;
dev = pci_get_bus_and_slot(bus, dfn);
--
1.7.11.2
From 4c02feefb934d587f03c74cc48e8d58904416c68 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Thu, 8 Mar 2012 10:35:59 -0500
Subject: [PATCH 03/13] x86: Lock down IO port access in secure boot
environments
IO port access would permit users to gain access to PCI configuration
registers, which in turn (on a lot of hardware) give access to MMIO register
space. This would potentially permit root to trigger arbitrary DMA, so lock
it down by default.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
arch/x86/kernel/ioport.c | 4 ++--
drivers/char/mem.c | 3 +++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 8c96897..c3a1bb2 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -28,7 +28,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)
if ((from + num <= from) || (from + num > IO_BITMAP_BITS))
return -EINVAL;
- if (turn_on && !capable(CAP_SYS_RAWIO))
+ if (turn_on && (!capable(CAP_SYS_RAWIO) || !capable(CAP_SECURE_FIRMWARE)))
return -EPERM;
/*
@@ -102,7 +102,7 @@ long sys_iopl(unsigned int level, struct pt_regs *regs)
return -EINVAL;
/* Trying to gain more privileges? */
if (level > old) {
- if (!capable(CAP_SYS_RAWIO))
+ if (!capable(CAP_SYS_RAWIO) || !capable(CAP_SECURE_FIRMWARE))
return -EPERM;
}
regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index e5eedfa..8f5f872 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -597,6 +597,9 @@ static ssize_t write_port(struct file *file, const char __user *buf,
unsigned long i = *ppos;
const char __user * tmp = buf;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
while (count-- > 0 && i < 65536) {
--
1.7.11.2
From d379d102316075d51011b81748433530d294a70c Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Fri, 9 Mar 2012 08:39:37 -0500
Subject: [PATCH 04/13] ACPI: Limit access to custom_method
It must be impossible for even root to get code executed in kernel context
under a secure boot environment. custom_method effectively allows arbitrary
access to system memory, so it needs to have a capability check here.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
drivers/acpi/custom_method.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
index 5d42c24..3e78014 100644
--- a/drivers/acpi/custom_method.c
+++ b/drivers/acpi/custom_method.c
@@ -29,6 +29,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,
struct acpi_table_header table;
acpi_status status;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
if (!(*ppos)) {
/* parse the table header to get the table length */
if (count <= sizeof(struct acpi_table_header))
--
1.7.11.2
From afc7c002eb264fc745a38fb6ec322be4928338dd Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Fri, 9 Mar 2012 08:46:50 -0500
Subject: [PATCH 05/13] asus-wmi: Restrict debugfs interface
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
be manipulated in such a way that arbitrary code can be executed in the
kernel. Add a capability check to prevent that.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
drivers/platform/x86/asus-wmi.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index c7a36f6..0fb58bc 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -1509,6 +1509,9 @@ static int show_dsts(struct seq_file *m, void *data)
int err;
u32 retval = -1;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval);
if (err < 0)
@@ -1525,6 +1528,9 @@ static int show_devs(struct seq_file *m, void *data)
int err;
u32 retval = -1;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param,
&retval);
@@ -1549,6 +1555,9 @@ static int show_call(struct seq_file *m, void *data)
union acpi_object *obj;
acpi_status status;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID,
1, asus->debug.method_id,
&input, &output);
--
1.7.11.2
From 21bd1f0da09b40a0ba50636267f7eac8f839a336 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Fri, 9 Mar 2012 09:28:15 -0500
Subject: [PATCH 06/13] Restrict /dev/mem and /dev/kmem in secure boot setups
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 8f5f872..c1de8e1 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;
void *ptr;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ 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,
char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
int err = 0;
+ if (!capable(CAP_SECURE_FIRMWARE))
+ return -EPERM;
+
if (p < (unsigned long) high_memory) {
unsigned long to_write = min_t(unsigned long, count,
(unsigned long)high_memory - p);
--
1.7.11.2
From 1940a18cd651113f5b46f5a41290065963d6fbad Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Fri, 9 Mar 2012 11:47:56 -0500
Subject: [PATCH 07/13] 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..48852ec 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_SECURE_FIRMWARE))
return -EPERM;
/*
--
1.7.11.2
From c83bad5d60b8f02ebbedf9b4c4b69cdee49a7976 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Mon, 25 Jun 2012 19:45:15 -0400
Subject: [PATCH 08/13] Secure boot: Add a dummy kernel parameter that will
switch on Secure Boot mode
This forcibly drops CAP_SECURE_FIRMWARE 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>
---
kernel/cred.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/kernel/cred.c b/kernel/cred.c
index de728ac..0d71d02 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -623,6 +623,20 @@ void __init cred_init(void)
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
}
+/* Dummy Secure Boot enable option to fake out UEFI SB=1 */
+static int __init secureboot_enable(char *str)
+{
+
+ int sb_enable = !!simple_strtol(str, NULL, 0);
+ pr_info("Secure Boot mode %s\n", (sb_enable ? "enabled" : "disabled"));
+ if (sb_enable) {
+ cap_lower((&init_cred)->cap_bset, CAP_SECURE_FIRMWARE);
+ cap_lower((&init_cred)->cap_permitted, CAP_SECURE_FIRMWARE);
+ }
+ return 1;
+}
+__setup("secureboot_enable=", secureboot_enable);
+
/**
* prepare_kernel_cred - Prepare a set of credentials for a kernel service
* @daemon: A userspace daemon to be used as a reference
--
1.7.11.2
From b70595f1523ecadc4ce9d43e9a0c465436ed1007 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Wed, 18 Jul 2012 11:28:00 -0400
Subject: [PATCH 09/13] 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>
---
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 ++
kernel/cred.c | 18 +++++++++++-------
5 files changed, 50 insertions(+), 8 deletions(-)
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
*/
diff --git a/kernel/cred.c b/kernel/cred.c
index 0d71d02..c43e2b0 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -623,19 +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_SECURE_FIRMWARE);
+ cap_lower((&init_cred)->cap_permitted, CAP_SECURE_FIRMWARE);
+}
+
/* Dummy Secure Boot enable option to fake out UEFI SB=1 */
-static int __init secureboot_enable(char *str)
+static int __init secureboot_enable_opt(char *str)
{
int sb_enable = !!simple_strtol(str, NULL, 0);
- pr_info("Secure Boot mode %s\n", (sb_enable ? "enabled" : "disabled"));
- if (sb_enable) {
- cap_lower((&init_cred)->cap_bset, CAP_SECURE_FIRMWARE);
- cap_lower((&init_cred)->cap_permitted, CAP_SECURE_FIRMWARE);
- }
+ if (sb_enable)
+ secureboot_enable();
return 1;
}
-__setup("secureboot_enable=", secureboot_enable);
+__setup("secureboot_enable=", secureboot_enable_opt);
/**
* prepare_kernel_cred - Prepare a set of credentials for a kernel service
--
1.7.11.2
From 411c18c35ccacb1a9e3f3dc67383a6431e110e17 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Mon, 25 Jun 2012 19:57:30 -0400
Subject: [PATCH 10/13] 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_SECURE_FIRMWARE 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..50c94e4 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_SECURE_FIRMWARE))
return acpi_rsdp;
#endif
--
1.7.11.2
From 7bf87e8da8c7b57ba7f9448855c8ec84c684fb65 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Mon, 25 Jun 2012 21:29:46 -0400
Subject: [PATCH 11/13] 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 ad7e2e5..33c4029 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.
--
1.7.11.2
From ec0ca55ba3d1c2a59b0c0b6e38f7ae9966d676aa Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Tue, 26 Jun 2012 14:15:51 -0400
Subject: [PATCH 12/13] 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_SECURE_FIRMWARE 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..0a1e348 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", "secure_firmware", NULL } },
{ "kernel_service", { "use_as_override", "create_files_as", NULL } },
{ "tun_socket",
{ COMMON_SOCK_PERMS, NULL } },
--
1.7.11.2
From 0a90e99e45f5c8eddd3b8cfcd63a4c6355c5688d Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Tue, 26 Jun 2012 16:27:26 -0400
Subject: [PATCH 13/13] modsign: Reject unsigned modules 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. We add a
capability check and reject modules that are not signed.
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
---
kernel/module-verify.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/module-verify.c b/kernel/module-verify.c
index 22036d4..f6821b3 100644
--- a/kernel/module-verify.c
+++ b/kernel/module-verify.c
@@ -31,6 +31,7 @@
#include <linux/modsign.h>
#include <linux/moduleparam.h>
#include <linux/fips.h>
+#include <linux/capability.h>
#include <keys/crypto-type.h>
#include "module-verify.h"
#include "module-verify-defs.h"
@@ -699,7 +700,7 @@ int module_verify(const Elf_Ehdr *hdr, size_t size, bool *_gpgsig_ok)
/* The ELF checker found the sig for us if it exists */
if (mvdata.sig_index <= 0) {
/* Deal with an unsigned module */
- if (modsign_signedonly) {
+ if (modsign_signedonly || !capable(CAP_SECURE_FIRMWARE)) {
pr_err("An attempt to load unsigned module was rejected\n");
return -EKEYREJECTED;
} else {
@@ -736,7 +737,7 @@ out:
break;
case -ENOKEY: /* Signed, but we don't have the public key */
pr_err("Module signed with unknown public key\n");
- if (!modsign_signedonly) {
+ if (!modsign_signedonly && capable(CAP_SECURE_FIRMWARE)) {
/* Allow a module to be signed with an unknown public
* key unless we're enforcing.
*/
--
1.7.11.2