diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/Kconfig | 9 | ||||
| -rw-r--r-- | security/integrity/Makefile | 7 | ||||
| -rw-r--r-- | security/integrity/ima/ima.h | 11 | ||||
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 33 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 70 | ||||
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 12 | ||||
| -rw-r--r-- | security/integrity/integrity.h | 1 | ||||
| -rw-r--r-- | security/integrity/platform_certs/keyring_handler.c | 80 | ||||
| -rw-r--r-- | security/integrity/platform_certs/keyring_handler.h | 32 | ||||
| -rw-r--r-- | security/integrity/platform_certs/load_powerpc.c | 96 | ||||
| -rw-r--r-- | security/integrity/platform_certs/load_uefi.c | 72 | ||||
| -rw-r--r-- | security/lockdown/lockdown.c | 2 |
12 files changed, 328 insertions, 97 deletions
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig index 0bae6adb63a9..71f0177e8716 100644 --- a/security/integrity/Kconfig +++ b/security/integrity/Kconfig @@ -72,6 +72,15 @@ config LOAD_IPL_KEYS depends on S390 def_bool y +config LOAD_PPC_KEYS + bool "Enable loading of platform and blacklisted keys for POWER" + depends on INTEGRITY_PLATFORM_KEYRING + depends on PPC_SECURE_BOOT + default y + help + Enable loading of keys to the .platform keyring and blacklisted + hashes to the .blacklist keyring for powerpc based platforms. + config INTEGRITY_AUDIT bool "Enables integrity auditing support " depends on AUDIT diff --git a/security/integrity/Makefile b/security/integrity/Makefile index 35e6ca773734..7ee39d66cf16 100644 --- a/security/integrity/Makefile +++ b/security/integrity/Makefile @@ -11,8 +11,11 @@ integrity-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o integrity-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \ - platform_certs/load_uefi.o + platform_certs/load_uefi.o \ + platform_certs/keyring_handler.o integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o - +integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \ + platform_certs/load_powerpc.o \ + platform_certs/keyring_handler.o obj-$(CONFIG_IMA) += ima/ obj-$(CONFIG_EVM) += evm/ diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 3689081aaf38..df4ca482fb53 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -217,6 +217,9 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, struct evm_ima_xattr_data *xattr_value, int xattr_len, const struct modsig *modsig, int pcr, struct ima_template_desc *template_desc); +void process_buffer_measurement(const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr); void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, @@ -253,6 +256,8 @@ int ima_policy_show(struct seq_file *m, void *v); #define IMA_APPRAISE_KEXEC 0x40 #ifdef CONFIG_IMA_APPRAISE +int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr); int ima_appraise_measurement(enum ima_hooks func, struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, @@ -268,6 +273,12 @@ int ima_read_xattr(struct dentry *dentry, struct evm_ima_xattr_data **xattr_value); #else +static inline int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr) +{ + return 0; +} + static inline int ima_appraise_measurement(enum ima_hooks func, struct integrity_iint_cache *iint, struct file *file, diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 136ae4e0ee92..300c8d2943c5 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -12,6 +12,7 @@ #include <linux/magic.h> #include <linux/ima.h> #include <linux/evm.h> +#include <keys/system_keyring.h> #include "ima.h" @@ -304,6 +305,38 @@ static int modsig_verify(enum ima_hooks func, const struct modsig *modsig, } /* + * ima_check_blacklist - determine if the binary is blacklisted. + * + * Add the hash of the blacklisted binary to the measurement list, based + * on policy. + * + * Returns -EPERM if the hash is blacklisted. + */ +int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr) +{ + enum hash_algo hash_algo; + const u8 *digest = NULL; + u32 digestsize = 0; + int rc = 0; + + if (!(iint->flags & IMA_CHECK_BLACKLIST)) + return 0; + + if (iint->flags & IMA_MODSIG_ALLOWED && modsig) { + ima_get_modsig_digest(modsig, &hash_algo, &digest, &digestsize); + + rc = is_binary_blacklisted(digest, digestsize); + if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) + process_buffer_measurement(digest, digestsize, + "blacklisted-hash", NONE, + pcr); + } + + return rc; +} + +/* * ima_appraise_measurement - appraise file measurement * * Call evm_verifyxattr() to verify the integrity of 'security.ima'. diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 60027c643ecd..d7e987baf127 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -335,10 +335,14 @@ static int process_measurement(struct file *file, const struct cred *cred, xattr_value, xattr_len, modsig, pcr, template_desc); if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) { - inode_lock(inode); - rc = ima_appraise_measurement(func, iint, file, pathname, - xattr_value, xattr_len, modsig); - inode_unlock(inode); + rc = ima_check_blacklist(iint, modsig, pcr); + if (rc != -EPERM) { + inode_lock(inode); + rc = ima_appraise_measurement(func, iint, file, + pathname, xattr_value, + xattr_len, modsig); + inode_unlock(inode); + } if (!rc) rc = mmap_violation_check(func, file, &pathbuf, &pathname, filename); @@ -626,14 +630,14 @@ int ima_load_data(enum kernel_load_data_id id) * @buf: pointer to the buffer that needs to be added to the log. * @size: size of buffer(in bytes). * @eventname: event name to be used for the buffer entry. - * @cred: a pointer to a credentials structure for user validation. - * @secid: the secid of the task to be validated. + * @func: IMA hook + * @pcr: pcr to extend the measurement * * Based on policy, the buffer is measured into the ima log. */ -static void process_buffer_measurement(const void *buf, int size, - const char *eventname, - const struct cred *cred, u32 secid) +void process_buffer_measurement(const void *buf, int size, + const char *eventname, enum ima_hooks func, + int pcr) { int ret = 0; struct ima_template_entry *entry = NULL; @@ -642,19 +646,45 @@ static void process_buffer_measurement(const void *buf, int size, .filename = eventname, .buf = buf, .buf_len = size}; - struct ima_template_desc *template_desc = NULL; + struct ima_template_desc *template = NULL; struct { struct ima_digest_data hdr; char digest[IMA_MAX_DIGEST_SIZE]; } hash = {}; int violation = 0; - int pcr = CONFIG_IMA_MEASURE_PCR_IDX; int action = 0; + u32 secid; - action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr, - &template_desc); - if (!(action & IMA_MEASURE)) - return; + /* + * Both LSM hooks and auxilary based buffer measurements are + * based on policy. To avoid code duplication, differentiate + * between the LSM hooks and auxilary buffer measurements, + * retrieving the policy rule information only for the LSM hook + * buffer measurements. + */ + if (func) { + security_task_getsecid(current, &secid); + action = ima_get_action(NULL, current_cred(), secid, 0, func, + &pcr, &template); + if (!(action & IMA_MEASURE)) + return; + } + + if (!pcr) + pcr = CONFIG_IMA_MEASURE_PCR_IDX; + + if (!template) { + template = lookup_template_desc("ima-buf"); + ret = template_desc_init_fields(template->fmt, + &(template->fields), + &(template->num_fields)); + if (ret < 0) { + pr_err("template %s init failed, result: %d\n", + (strlen(template->name) ? + template->name : template->fmt), ret); + return; + } + } iint.ima_hash = &hash.hdr; iint.ima_hash->algo = ima_hash_algo; @@ -664,7 +694,7 @@ static void process_buffer_measurement(const void *buf, int size, if (ret < 0) goto out; - ret = ima_alloc_init_template(&event_data, &entry, template_desc); + ret = ima_alloc_init_template(&event_data, &entry, template); if (ret < 0) goto out; @@ -686,13 +716,9 @@ out: */ void ima_kexec_cmdline(const void *buf, int size) { - u32 secid; - - if (buf && size != 0) { - security_task_getsecid(current, &secid); + if (buf && size != 0) process_buffer_measurement(buf, size, "kexec-cmdline", - current_cred(), secid); - } + KEXEC_CMDLINE, 0); } static int __init init_ima(void) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 5380aca2b351..f19a895ad7cd 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -765,8 +765,8 @@ enum { Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq, Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt, Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, - Opt_appraise_type, Opt_permit_directio, - Opt_pcr, Opt_template, Opt_err + Opt_appraise_type, Opt_appraise_flag, + Opt_permit_directio, Opt_pcr, Opt_template, Opt_err }; static const match_table_t policy_tokens = { @@ -798,6 +798,7 @@ static const match_table_t policy_tokens = { {Opt_euid_lt, "euid<%s"}, {Opt_fowner_lt, "fowner<%s"}, {Opt_appraise_type, "appraise_type=%s"}, + {Opt_appraise_flag, "appraise_flag=%s"}, {Opt_permit_directio, "permit_directio"}, {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, @@ -1172,6 +1173,11 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else result = -EINVAL; break; + case Opt_appraise_flag: + ima_log_string(ab, "appraise_flag", args[0].from); + if (strstr(args[0].from, "blacklist")) + entry->flags |= IMA_CHECK_BLACKLIST; + break; case Opt_permit_directio: entry->flags |= IMA_PERMIT_DIRECTIO; break; @@ -1500,6 +1506,8 @@ int ima_policy_show(struct seq_file *m, void *v) else seq_puts(m, "appraise_type=imasig "); } + if (entry->flags & IMA_CHECK_BLACKLIST) + seq_puts(m, "appraise_flag=check_blacklist "); if (entry->flags & IMA_PERMIT_DIRECTIO) seq_puts(m, "permit_directio "); rcu_read_unlock(); diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index d9323d31a3a8..73fc286834d7 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -32,6 +32,7 @@ #define EVM_IMMUTABLE_DIGSIG 0x08000000 #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 #define IMA_MODSIG_ALLOWED 0x20000000 +#define IMA_CHECK_BLACKLIST 0x40000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_HASH | IMA_APPRAISE_SUBMASK) diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c new file mode 100644 index 000000000000..c5ba695c10e3 --- /dev/null +++ b/security/integrity/platform_certs/keyring_handler.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/efi.h> +#include <linux/slab.h> +#include <keys/asymmetric-type.h> +#include <keys/system_keyring.h> +#include "../integrity.h" + +static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID; +static efi_guid_t efi_cert_x509_sha256_guid __initdata = + EFI_CERT_X509_SHA256_GUID; +static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID; + +/* + * Blacklist a hash. + */ +static __init void uefi_blacklist_hash(const char *source, const void *data, + size_t len, const char *type, + size_t type_len) +{ + char *hash, *p; + + hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL); + if (!hash) + return; + p = memcpy(hash, type, type_len); + p += type_len; + bin2hex(p, data, len); + p += len * 2; + *p = 0; + + mark_hash_blacklisted(hash); + kfree(hash); +} + +/* + * Blacklist an X509 TBS hash. + */ +static __init void uefi_blacklist_x509_tbs(const char *source, + const void *data, size_t len) +{ + uefi_blacklist_hash(source, data, len, "tbs:", 4); +} + +/* + * Blacklist the hash of an executable. + */ +static __init void uefi_blacklist_binary(const char *source, + const void *data, size_t len) +{ + uefi_blacklist_hash(source, data, len, "bin:", 4); +} + +/* + * Return the appropriate handler for particular signature list types found in + * the UEFI db and MokListRT tables. + */ +__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type) +{ + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) + return add_to_platform_keyring; + return 0; +} + +/* + * Return the appropriate handler for particular signature list types found in + * the UEFI dbx and MokListXRT tables. + */ +__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) +{ + if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0) + return uefi_blacklist_x509_tbs; + if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) + return uefi_blacklist_binary; + return 0; +} diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h new file mode 100644 index 000000000000..2462bfa08fe3 --- /dev/null +++ b/security/integrity/platform_certs/keyring_handler.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef PLATFORM_CERTS_INTERNAL_H +#define PLATFORM_CERTS_INTERNAL_H + +#include <linux/efi.h> + +void blacklist_hash(const char *source, const void *data, + size_t len, const char *type, + size_t type_len); + +/* + * Blacklist an X509 TBS hash. + */ +void blacklist_x509_tbs(const char *source, const void *data, size_t len); + +/* + * Blacklist the hash of an executable. + */ +void blacklist_binary(const char *source, const void *data, size_t len); + +/* + * Return the handler for particular signature list types found in the db. + */ +efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type); + +/* + * Return the handler for particular signature list types found in the dbx. + */ +efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type); + +#endif diff --git a/security/integrity/platform_certs/load_powerpc.c b/security/integrity/platform_certs/load_powerpc.c new file mode 100644 index 000000000000..a2900cb85357 --- /dev/null +++ b/security/integrity/platform_certs/load_powerpc.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain + * + * - loads keys and hashes stored and controlled by the firmware. + */ +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cred.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <asm/secure_boot.h> +#include <asm/secvar.h> +#include "keyring_handler.h" + +/* + * Get a certificate list blob from the named secure variable. + */ +static __init void *get_cert_list(u8 *key, unsigned long keylen, uint64_t *size) +{ + int rc; + void *db; + + rc = secvar_ops->get(key, keylen, NULL, size); + if (rc) { + pr_err("Couldn't get size: %d\n", rc); + return NULL; + } + + db = kmalloc(*size, GFP_KERNEL); + if (!db) + return NULL; + + rc = secvar_ops->get(key, keylen, db, size); + if (rc) { + kfree(db); + pr_err("Error reading %s var: %d\n", key, rc); + return NULL; + } + + return db; +} + +/* + * Load the certs contained in the keys databases into the platform trusted + * keyring and the blacklisted X.509 cert SHA256 hashes into the blacklist + * keyring. + */ +static int __init load_powerpc_certs(void) +{ + void *db = NULL, *dbx = NULL; + uint64_t dbsize = 0, dbxsize = 0; + int rc = 0; + struct device_node *node; + + if (!secvar_ops) + return -ENODEV; + + /* The following only applies for the edk2-compat backend. */ + node = of_find_compatible_node(NULL, NULL, "ibm,edk2-compat-v1"); + if (!node) + return -ENODEV; + + /* + * Get db, and dbx. They might not exist, so it isn't an error if we + * can't get them. + */ + db = get_cert_list("db", 3, &dbsize); + if (!db) { + pr_err("Couldn't get db list from firmware\n"); + } else { + rc = parse_efi_signature_list("powerpc:db", db, dbsize, + get_handler_for_db); + if (rc) + pr_err("Couldn't parse db signatures: %d\n", rc); + kfree(db); + } + + dbx = get_cert_list("dbx", 4, &dbxsize); + if (!dbx) { + pr_info("Couldn't get dbx list from firmware\n"); + } else { + rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize, + get_handler_for_dbx); + if (rc) + pr_err("Couldn't parse dbx signatures: %d\n", rc); + kfree(dbx); + } + + of_node_put(node); + + return rc; +} +late_initcall(load_powerpc_certs); diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index 81b19c52832b..111898aad56e 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -9,11 +9,7 @@ #include <keys/asymmetric-type.h> #include <keys/system_keyring.h> #include "../integrity.h" - -static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID; -static efi_guid_t efi_cert_x509_sha256_guid __initdata = - EFI_CERT_X509_SHA256_GUID; -static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID; +#include "keyring_handler.h" /* * Look to see if a UEFI variable called MokIgnoreDB exists and return true if @@ -68,72 +64,6 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, } /* - * Blacklist a hash. - */ -static __init void uefi_blacklist_hash(const char *source, const void *data, - size_t len, const char *type, - size_t type_len) -{ - char *hash, *p; - - hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL); - if (!hash) - return; - p = memcpy(hash, type, type_len); - p += type_len; - bin2hex(p, data, len); - p += len * 2; - *p = 0; - - mark_hash_blacklisted(hash); - kfree(hash); -} - -/* - * Blacklist an X509 TBS hash. - */ -static __init void uefi_blacklist_x509_tbs(const char *source, - const void *data, size_t len) -{ - uefi_blacklist_hash(source, data, len, "tbs:", 4); -} - -/* - * Blacklist the hash of an executable. - */ -static __init void uefi_blacklist_binary(const char *source, - const void *data, size_t len) -{ - uefi_blacklist_hash(source, data, len, "bin:", 4); -} - -/* - * Return the appropriate handler for particular signature list types found in - * the UEFI db and MokListRT tables. - */ -static __init efi_element_handler_t get_handler_for_db(const efi_guid_t * - sig_type) -{ - if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) - return add_to_platform_keyring; - return 0; -} - -/* - * Return the appropriate handler for particular signature list types found in - * the UEFI dbx and MokListXRT tables. - */ -static __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t * - sig_type) -{ - if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0) - return uefi_blacklist_x509_tbs; - if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) - return uefi_blacklist_binary; - return 0; -} - -/* * Load the certs contained in the UEFI databases into the platform trusted * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist * keyring. diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index 40b790536def..b2f87015d6e9 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -32,12 +32,14 @@ static const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = { [LOCKDOWN_MODULE_PARAMETERS] = "unsafe module parameters", [LOCKDOWN_MMIOTRACE] = "unsafe mmio", [LOCKDOWN_DEBUGFS] = "debugfs access", + [LOCKDOWN_XMON_WR] = "xmon write access", [LOCKDOWN_INTEGRITY_MAX] = "integrity", [LOCKDOWN_KCORE] = "/proc/kcore access", [LOCKDOWN_KPROBES] = "use of kprobes", [LOCKDOWN_BPF_READ] = "use of bpf to read kernel RAM", [LOCKDOWN_PERF] = "unsafe use of perf", [LOCKDOWN_TRACEFS] = "use of tracefs", + [LOCKDOWN_XMON_RW] = "xmon read and write access", [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality", }; |