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authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-28 08:14:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-28 08:14:15 -0700
commitaefcf2f4b58155d27340ba5f9ddbe9513da8286d (patch)
treea8ae994ca71b2e43e3075c796165e5ed62e28e42 /arch
parentf1f2f614d535564992f32e720739cb53cf03489f (diff)
parent45893a0abee6b5fd52994a3a1095735aeaec472b (diff)
downloadlinux-aefcf2f4b58155d27340ba5f9ddbe9513da8286d.tar.gz
Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/Kconfig6
-rw-r--r--arch/s390/Kconfig2
-rw-r--r--arch/s390/kernel/kexec_elf.c4
-rw-r--r--arch/s390/kernel/kexec_image.c4
-rw-r--r--arch/s390/kernel/machine_kexec_file.c4
-rw-r--r--arch/x86/Kconfig20
-rw-r--r--arch/x86/boot/compressed/acpi.c19
-rw-r--r--arch/x86/include/asm/acpi.h9
-rw-r--r--arch/x86/include/asm/x86_init.h2
-rw-r--r--arch/x86/kernel/acpi/boot.c5
-rw-r--r--arch/x86/kernel/ima_arch.c4
-rw-r--r--arch/x86/kernel/ioport.c7
-rw-r--r--arch/x86/kernel/kexec-bzimage64.c1
-rw-r--r--arch/x86/kernel/msr.c8
-rw-r--r--arch/x86/kernel/x86_init.c1
-rw-r--r--arch/x86/mm/testmmiotrace.c5
16 files changed, 76 insertions, 25 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 866e05882799..41a9b4257b72 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -982,7 +982,7 @@ config KEXEC_FILE
for kernel and initramfs as opposed to list of segments as
accepted by previous system call.
-config KEXEC_VERIFY_SIG
+config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE
help
@@ -997,13 +997,13 @@ config KEXEC_VERIFY_SIG
config KEXEC_IMAGE_VERIFY_SIG
bool "Enable Image signature verification support"
default y
- depends on KEXEC_VERIFY_SIG
+ depends on KEXEC_SIG
depends on EFI && SIGNED_PE_FILE_VERIFICATION
help
Enable Image signature verification support.
comment "Support for PE file signature verification disabled"
- depends on KEXEC_VERIFY_SIG
+ depends on KEXEC_SIG
depends on !EFI || !SIGNED_PE_FILE_VERIFICATION
config CRASH_DUMP
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 68f7c2b16ff7..43a81d0ad507 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -554,7 +554,7 @@ config ARCH_HAS_KEXEC_PURGATORY
def_bool y
depends on KEXEC_FILE
-config KEXEC_VERIFY_SIG
+config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE && MODULE_SIG_FORMAT
help
diff --git a/arch/s390/kernel/kexec_elf.c b/arch/s390/kernel/kexec_elf.c
index 6d0635ceddd0..9da6fa30c447 100644
--- a/arch/s390/kernel/kexec_elf.c
+++ b/arch/s390/kernel/kexec_elf.c
@@ -130,7 +130,7 @@ static int s390_elf_probe(const char *buf, unsigned long len)
const struct kexec_file_ops s390_kexec_elf_ops = {
.probe = s390_elf_probe,
.load = s390_elf_load,
-#ifdef CONFIG_KEXEC_VERIFY_SIG
+#ifdef CONFIG_KEXEC_SIG
.verify_sig = s390_verify_sig,
-#endif /* CONFIG_KEXEC_VERIFY_SIG */
+#endif /* CONFIG_KEXEC_SIG */
};
diff --git a/arch/s390/kernel/kexec_image.c b/arch/s390/kernel/kexec_image.c
index 58318bf89fd9..af23eff5774d 100644
--- a/arch/s390/kernel/kexec_image.c
+++ b/arch/s390/kernel/kexec_image.c
@@ -59,7 +59,7 @@ static int s390_image_probe(const char *buf, unsigned long len)
const struct kexec_file_ops s390_kexec_image_ops = {
.probe = s390_image_probe,
.load = s390_image_load,
-#ifdef CONFIG_KEXEC_VERIFY_SIG
+#ifdef CONFIG_KEXEC_SIG
.verify_sig = s390_verify_sig,
-#endif /* CONFIG_KEXEC_VERIFY_SIG */
+#endif /* CONFIG_KEXEC_SIG */
};
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index 1ac9fbc6e01e..8415ae7d2a23 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -22,7 +22,7 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
NULL,
};
-#ifdef CONFIG_KEXEC_VERIFY_SIG
+#ifdef CONFIG_KEXEC_SIG
int s390_verify_sig(const char *kernel, unsigned long kernel_len)
{
const unsigned long marker_len = sizeof(MODULE_SIG_STRING) - 1;
@@ -68,7 +68,7 @@ int s390_verify_sig(const char *kernel, unsigned long kernel_len)
VERIFYING_MODULE_SIGNATURE,
NULL, NULL);
}
-#endif /* CONFIG_KEXEC_VERIFY_SIG */
+#endif /* CONFIG_KEXEC_SIG */
static int kexec_file_update_purgatory(struct kimage *image,
struct s390_load_data *data)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 37ed5f5910d5..d6e1faa28c58 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2031,20 +2031,30 @@ config KEXEC_FILE
config ARCH_HAS_KEXEC_PURGATORY
def_bool KEXEC_FILE
-config KEXEC_VERIFY_SIG
+config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE
---help---
- This option makes kernel signature verification mandatory for
- the kexec_file_load() syscall.
- In addition to that option, you need to enable signature
+ This option makes the kexec_file_load() syscall check for a valid
+ signature of the kernel image. The image can still be loaded without
+ a valid signature unless you also enable KEXEC_SIG_FORCE, though if
+ there's a signature that we can check, then it must be valid.
+
+ In addition to this option, you need to enable signature
verification for the corresponding kernel image type being
loaded in order for this to work.
+config KEXEC_SIG_FORCE
+ bool "Require a valid signature in kexec_file_load() syscall"
+ depends on KEXEC_SIG
+ ---help---
+ This option makes kernel signature verification mandatory for
+ the kexec_file_load() syscall.
+
config KEXEC_BZIMAGE_VERIFY_SIG
bool "Enable bzImage signature verification support"
- depends on KEXEC_VERIFY_SIG
+ depends on KEXEC_SIG
depends on SIGNED_PE_FILE_VERIFICATION
select SYSTEM_TRUSTED_KEYRING
---help---
diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c
index 15255f388a85..149795c369f2 100644
--- a/arch/x86/boot/compressed/acpi.c
+++ b/arch/x86/boot/compressed/acpi.c
@@ -26,7 +26,7 @@ struct mem_vector immovable_mem[MAX_NUMNODES*2];
*/
#define MAX_ADDR_LEN 19
-static acpi_physical_address get_acpi_rsdp(void)
+static acpi_physical_address get_cmdline_acpi_rsdp(void)
{
acpi_physical_address addr = 0;
@@ -278,10 +278,7 @@ acpi_physical_address get_rsdp_addr(void)
{
acpi_physical_address pa;
- pa = get_acpi_rsdp();
-
- if (!pa)
- pa = boot_params->acpi_rsdp_addr;
+ pa = boot_params->acpi_rsdp_addr;
/*
* Try to get EFI data from setup_data. This can happen when we're a
@@ -311,7 +308,17 @@ static unsigned long get_acpi_srat_table(void)
char arg[10];
u8 *entry;
- rsdp = (struct acpi_table_rsdp *)(long)boot_params->acpi_rsdp_addr;
+ /*
+ * Check whether we were given an RSDP on the command line. We don't
+ * stash this in boot params because the kernel itself may have
+ * different ideas about whether to trust a command-line parameter.
+ */
+ rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp();
+
+ if (!rsdp)
+ rsdp = (struct acpi_table_rsdp *)(long)
+ boot_params->acpi_rsdp_addr;
+
if (!rsdp)
return 0;
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index aac686e1e005..bc9693c9107e 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -117,6 +117,12 @@ static inline bool acpi_has_cpu_in_madt(void)
return !!acpi_lapic;
}
+#define ACPI_HAVE_ARCH_SET_ROOT_POINTER
+static inline void acpi_arch_set_root_pointer(u64 addr)
+{
+ x86_init.acpi.set_root_pointer(addr);
+}
+
#define ACPI_HAVE_ARCH_GET_ROOT_POINTER
static inline u64 acpi_arch_get_root_pointer(void)
{
@@ -125,6 +131,7 @@ static inline u64 acpi_arch_get_root_pointer(void)
void acpi_generic_reduced_hw_init(void);
+void x86_default_set_root_pointer(u64 addr);
u64 x86_default_get_root_pointer(void);
#else /* !CONFIG_ACPI */
@@ -138,6 +145,8 @@ static inline void disable_acpi(void) { }
static inline void acpi_generic_reduced_hw_init(void) { }
+static inline void x86_default_set_root_pointer(u64 addr) { }
+
static inline u64 x86_default_get_root_pointer(void)
{
return 0;
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index ac0934189017..19435858df5f 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -134,10 +134,12 @@ struct x86_hyper_init {
/**
* struct x86_init_acpi - x86 ACPI init functions
+ * @set_root_poitner: set RSDP address
* @get_root_pointer: get RSDP address
* @reduced_hw_early_init: hardware reduced platform early init
*/
struct x86_init_acpi {
+ void (*set_root_pointer)(u64 addr);
u64 (*get_root_pointer)(void);
void (*reduced_hw_early_init)(void);
};
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 17b33ef604f3..04205ce127a1 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1760,6 +1760,11 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
e820__update_table_print();
}
+void x86_default_set_root_pointer(u64 addr)
+{
+ boot_params.acpi_rsdp_addr = addr;
+}
+
u64 x86_default_get_root_pointer(void)
{
return boot_params.acpi_rsdp_addr;
diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
index 4c407833faca..4d4f5d9faac3 100644
--- a/arch/x86/kernel/ima_arch.c
+++ b/arch/x86/kernel/ima_arch.c
@@ -74,9 +74,9 @@ bool arch_ima_get_secureboot(void)
/* secureboot arch rules */
static const char * const sb_arch_rules[] = {
-#if !IS_ENABLED(CONFIG_KEXEC_VERIFY_SIG)
+#if !IS_ENABLED(CONFIG_KEXEC_SIG)
"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
-#endif /* CONFIG_KEXEC_VERIFY_SIG */
+#endif /* CONFIG_KEXEC_SIG */
"measure func=KEXEC_KERNEL_CHECK",
#if !IS_ENABLED(CONFIG_MODULE_SIG)
"appraise func=MODULE_CHECK appraise_type=imasig",
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index 0fe1c8782208..61a89d3c0382 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -11,6 +11,7 @@
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/ioport.h>
+#include <linux/security.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/slab.h>
@@ -31,7 +32,8 @@ long ksys_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) ||
+ security_locked_down(LOCKDOWN_IOPORT)))
return -EPERM;
/*
@@ -126,7 +128,8 @@ SYSCALL_DEFINE1(iopl, unsigned int, level)
return -EINVAL;
/* Trying to gain more privileges? */
if (level > old) {
- if (!capable(CAP_SYS_RAWIO))
+ if (!capable(CAP_SYS_RAWIO) ||
+ security_locked_down(LOCKDOWN_IOPORT))
return -EPERM;
}
regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) |
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 5ebcd02cbca7..d2f4e706a428 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;
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 3db2252b958d..1547be359d7f 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -34,6 +34,7 @@
#include <linux/notifier.h>
#include <linux/uaccess.h>
#include <linux/gfp.h>
+#include <linux/security.h>
#include <asm/cpufeature.h>
#include <asm/msr.h>
@@ -79,6 +80,10 @@ static ssize_t msr_write(struct file *file, const char __user *buf,
int err = 0;
ssize_t bytes = 0;
+ err = security_locked_down(LOCKDOWN_MSR);
+ if (err)
+ return err;
+
if (count % 8)
return -EINVAL; /* Invalid chunk size */
@@ -130,6 +135,9 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
err = -EFAULT;
break;
}
+ err = security_locked_down(LOCKDOWN_MSR);
+ if (err)
+ break;
err = wrmsr_safe_regs_on_cpu(cpu, regs);
if (err)
break;
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 1bef687faf22..18a799c8fa28 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -95,6 +95,7 @@ struct x86_init_ops x86_init __initdata = {
},
.acpi = {
+ .set_root_pointer = x86_default_set_root_pointer,
.get_root_pointer = x86_default_get_root_pointer,
.reduced_hw_early_init = acpi_generic_reduced_hw_init,
},
diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c
index 0881e1ff1e58..a8bd952e136d 100644
--- a/arch/x86/mm/testmmiotrace.c
+++ b/arch/x86/mm/testmmiotrace.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/io.h>
#include <linux/mmiotrace.h>
+#include <linux/security.h>
static unsigned long mmio_address;
module_param_hw(mmio_address, ulong, iomem, 0);
@@ -115,6 +116,10 @@ static void do_test_bulk_ioremapping(void)
static int __init init(void)
{
unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
+ int ret = security_locked_down(LOCKDOWN_MMIOTRACE);
+
+ if (ret)
+ return ret;
if (mmio_address == 0) {
pr_err("you have to use the module argument mmio_address.\n");