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-rw-r--r--security/integrity/Kconfig2
-rw-r--r--security/integrity/digsig.c48
-rw-r--r--security/integrity/digsig_asymmetric.c4
-rw-r--r--security/integrity/evm/evm_main.c8
-rw-r--r--security/integrity/ima/Kconfig16
-rw-r--r--security/integrity/ima/Makefile1
-rw-r--r--security/integrity/ima/ima.h79
-rw-r--r--security/integrity/ima/ima_api.c61
-rw-r--r--security/integrity/ima/ima_appraise.c201
-rw-r--r--security/integrity/ima/ima_crypto.c10
-rw-r--r--security/integrity/ima/ima_init.c6
-rw-r--r--security/integrity/ima/ima_main.c145
-rw-r--r--security/integrity/ima/ima_modsig.c168
-rw-r--r--security/integrity/ima/ima_policy.c230
-rw-r--r--security/integrity/ima/ima_template.c52
-rw-r--r--security/integrity/ima/ima_template_lib.c85
-rw-r--r--security/integrity/ima/ima_template_lib.h8
-rw-r--r--security/integrity/integrity.h26
18 files changed, 984 insertions, 166 deletions
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index c352532b8f84..0bae6adb63a9 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -18,8 +18,8 @@ if INTEGRITY
config INTEGRITY_SIGNATURE
bool "Digital signature verification using multiple keyrings"
- depends on KEYS
default n
+ select KEYS
select SIGNATURE
help
This option enables digital signature verification support
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 4582bc26770a..ea1aae3d07b3 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -39,11 +39,10 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
#define restrict_link_to_ima restrict_link_by_builtin_trusted
#endif
-int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
- const char *digest, int digestlen)
+static struct key *integrity_keyring_from_id(const unsigned int id)
{
- if (id >= INTEGRITY_KEYRING_MAX || siglen < 2)
- return -EINVAL;
+ if (id >= INTEGRITY_KEYRING_MAX)
+ return ERR_PTR(-EINVAL);
if (!keyring[id]) {
keyring[id] =
@@ -52,25 +51,52 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
int err = PTR_ERR(keyring[id]);
pr_err("no %s keyring: %d\n", keyring_name[id], err);
keyring[id] = NULL;
- return err;
+ return ERR_PTR(err);
}
}
+ return keyring[id];
+}
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+ const char *digest, int digestlen)
+{
+ struct key *keyring;
+
+ if (siglen < 2)
+ return -EINVAL;
+
+ keyring = integrity_keyring_from_id(id);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
+
switch (sig[1]) {
case 1:
/* v1 API expect signature without xattr type */
- return digsig_verify(keyring[id], sig + 1, siglen - 1,
- digest, digestlen);
+ return digsig_verify(keyring, sig + 1, siglen - 1, digest,
+ digestlen);
case 2:
- return asymmetric_verify(keyring[id], sig, siglen,
- digest, digestlen);
+ return asymmetric_verify(keyring, sig, siglen, digest,
+ digestlen);
}
return -EOPNOTSUPP;
}
-static int __integrity_init_keyring(const unsigned int id, key_perm_t perm,
- struct key_restriction *restriction)
+int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig)
+{
+ struct key *keyring;
+
+ keyring = integrity_keyring_from_id(id);
+ if (IS_ERR(keyring))
+ return PTR_ERR(keyring);
+
+ return ima_modsig_verify(keyring, modsig);
+}
+
+static int __init __integrity_init_keyring(const unsigned int id,
+ key_perm_t perm,
+ struct key_restriction *restriction)
{
const struct cred *cred = current_cred();
int err = 0;
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index ad4b323ecea1..55aec161d0e1 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -35,7 +35,7 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
key_ref_t kref;
kref = keyring_search(make_key_ref(key, 1),
- &key_type_asymmetric, name);
+ &key_type_asymmetric, name, true);
if (!IS_ERR(kref)) {
pr_err("Key '%s' is in ima_blacklist_keyring\n", name);
return ERR_PTR(-EKEYREJECTED);
@@ -47,7 +47,7 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
key_ref_t kref;
kref = keyring_search(make_key_ref(keyring, 1),
- &key_type_asymmetric, name);
+ &key_type_asymmetric, name, true);
if (IS_ERR(kref))
key = ERR_CAST(kref);
else
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 5bbd8b4dc29a..f9a81b187fae 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -166,7 +166,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
/* check value type */
switch (xattr_data->type) {
case EVM_XATTR_HMAC:
- if (xattr_len != sizeof(struct evm_ima_xattr_data)) {
+ if (xattr_len != sizeof(struct evm_xattr)) {
evm_status = INTEGRITY_FAIL;
goto out;
}
@@ -176,7 +176,7 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
xattr_value_len, &digest);
if (rc)
break;
- rc = crypto_memneq(xattr_data->digest, digest.digest,
+ rc = crypto_memneq(xattr_data->data, digest.digest,
SHA1_DIGEST_SIZE);
if (rc)
rc = -EINVAL;
@@ -520,7 +520,7 @@ int evm_inode_init_security(struct inode *inode,
const struct xattr *lsm_xattr,
struct xattr *evm_xattr)
{
- struct evm_ima_xattr_data *xattr_data;
+ struct evm_xattr *xattr_data;
int rc;
if (!evm_key_loaded() || !evm_protected_xattr(lsm_xattr->name))
@@ -530,7 +530,7 @@ int evm_inode_init_security(struct inode *inode,
if (!xattr_data)
return -ENOMEM;
- xattr_data->type = EVM_XATTR_HMAC;
+ xattr_data->data.type = EVM_XATTR_HMAC;
rc = evm_init_hmac(inode, lsm_xattr, xattr_data->digest);
if (rc < 0)
goto out;
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 32cd25fa44a5..838476d780e5 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -160,7 +160,8 @@ config IMA_APPRAISE
config IMA_ARCH_POLICY
bool "Enable loading an IMA architecture specific policy"
- depends on KEXEC_SIG || IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS
+ depends on (KEXEC_SIG && IMA) || IMA_APPRAISE \
+ && INTEGRITY_ASYMMETRIC_KEYS
default n
help
This option enables loading an IMA architecture specific policy
@@ -232,6 +233,19 @@ config IMA_APPRAISE_BOOTPARAM
This option enables the different "ima_appraise=" modes
(eg. fix, log) from the boot command line.
+config IMA_APPRAISE_MODSIG
+ bool "Support module-style signatures for appraisal"
+ depends on IMA_APPRAISE
+ depends on INTEGRITY_ASYMMETRIC_KEYS
+ select PKCS7_MESSAGE_PARSER
+ select MODULE_SIG_FORMAT
+ default n
+ help
+ Adds support for signatures appended to files. The format of the
+ appended signature is the same used for signed kernel modules.
+ The modsig keyword can be used in the IMA policy to allow a hook
+ to accept such signatures.
+
config IMA_TRUSTED_KEYRING
bool "Require all keys on the .ima keyring be signed (deprecated)"
depends on IMA_APPRAISE && SYSTEM_TRUSTED_KEYRING
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index d921dc4f9eb0..31d57cdf2421 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -9,5 +9,6 @@ obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
ima_policy.o ima_template.o ima_template_lib.o
ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
+ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o
ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 874bd77d3b91..3689081aaf38 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -60,7 +60,10 @@ struct ima_event_data {
const unsigned char *filename;
struct evm_ima_xattr_data *xattr_value;
int xattr_len;
+ const struct modsig *modsig;
const char *violation;
+ const void *buf;
+ int buf_len;
};
/* IMA template field data definition */
@@ -144,7 +147,12 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
int ima_init_crypto(void);
void ima_putc(struct seq_file *m, void *data, int datalen);
void ima_print_digest(struct seq_file *m, u8 *digest, u32 size);
+int template_desc_init_fields(const char *template_fmt,
+ const struct ima_template_field ***fields,
+ int *num_fields);
struct ima_template_desc *ima_template_desc_current(void);
+struct ima_template_desc *lookup_template_desc(const char *name);
+bool ima_template_has_modsig(const struct ima_template_desc *ima_template);
int ima_restore_measurement_entry(struct ima_template_entry *entry);
int ima_restore_measurement_list(loff_t bufsize, void *buf);
int ima_measurements_show(struct seq_file *m, void *v);
@@ -152,6 +160,8 @@ unsigned long ima_get_binary_runtime_size(void);
int ima_init_template(void);
void ima_init_template_list(void);
int __init ima_init_digests(void);
+int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
+ void *lsm_data);
/*
* used to protect h_table and sha_table
@@ -182,6 +192,7 @@ static inline unsigned long ima_hash_key(u8 *digest)
hook(KEXEC_KERNEL_CHECK) \
hook(KEXEC_INITRAMFS_CHECK) \
hook(POLICY_CHECK) \
+ hook(KEXEC_CMDLINE) \
hook(MAX_CHECK)
#define __ima_hook_enumify(ENUM) ENUM,
@@ -189,21 +200,28 @@ enum ima_hooks {
__ima_hooks(__ima_hook_enumify)
};
+extern const char *const func_tokens[];
+
+struct modsig;
+
/* LIM API function definitions */
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
- int mask, enum ima_hooks func, int *pcr);
+ int mask, enum ima_hooks func, int *pcr,
+ struct ima_template_desc **template_desc);
int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file, void *buf, loff_t size,
- enum hash_algo algo);
+ enum hash_algo algo, struct modsig *modsig);
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len, int pcr);
+ int xattr_len, const struct modsig *modsig, int pcr,
+ struct ima_template_desc *template_desc);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
- struct ima_template_entry **entry);
+ struct ima_template_entry **entry,
+ struct ima_template_desc *template_desc);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode,
const unsigned char *filename, int pcr);
@@ -212,7 +230,8 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
/* IMA policy related functions */
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask, int flags, int *pcr);
+ enum ima_hooks func, int mask, int flags, int *pcr,
+ struct ima_template_desc **template_desc);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flag(void);
@@ -238,7 +257,7 @@ int ima_appraise_measurement(enum ima_hooks func,
struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len);
+ int xattr_len, const struct modsig *modsig);
int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
@@ -254,7 +273,8 @@ static inline int ima_appraise_measurement(enum ima_hooks func,
struct file *file,
const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len)
+ int xattr_len,
+ const struct modsig *modsig)
{
return INTEGRITY_UNKNOWN;
}
@@ -291,6 +311,51 @@ static inline int ima_read_xattr(struct dentry *dentry,
#endif /* CONFIG_IMA_APPRAISE */
+#ifdef CONFIG_IMA_APPRAISE_MODSIG
+bool ima_hook_supports_modsig(enum ima_hooks func);
+int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
+ struct modsig **modsig);
+void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size);
+int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
+ const u8 **digest, u32 *digest_size);
+int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
+ u32 *data_len);
+void ima_free_modsig(struct modsig *modsig);
+#else
+static inline bool ima_hook_supports_modsig(enum ima_hooks func)
+{
+ return false;
+}
+
+static inline int ima_read_modsig(enum ima_hooks func, const void *buf,
+ loff_t buf_len, struct modsig **modsig)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void ima_collect_modsig(struct modsig *modsig, const void *buf,
+ loff_t size)
+{
+}
+
+static inline int ima_get_modsig_digest(const struct modsig *modsig,
+ enum hash_algo *algo, const u8 **digest,
+ u32 *digest_size)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int ima_get_raw_modsig(const struct modsig *modsig,
+ const void **data, u32 *data_len)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void ima_free_modsig(struct modsig *modsig)
+{
+}
+#endif /* CONFIG_IMA_APPRAISE_MODSIG */
+
/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 35c129cbb7e9..610759fe63b8 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -34,13 +34,19 @@ void ima_free_template_entry(struct ima_template_entry *entry)
* ima_alloc_init_template - create and initialize a new template entry
*/
int ima_alloc_init_template(struct ima_event_data *event_data,
- struct ima_template_entry **entry)
+ struct ima_template_entry **entry,
+ struct ima_template_desc *desc)
{
- struct ima_template_desc *template_desc = ima_template_desc_current();
+ struct ima_template_desc *template_desc;
int i, result = 0;
- *entry = kzalloc(sizeof(**entry) + template_desc->num_fields *
- sizeof(struct ima_field_data), GFP_NOFS);
+ if (desc)
+ template_desc = desc;
+ else
+ template_desc = ima_template_desc_current();
+
+ *entry = kzalloc(struct_size(*entry, template_data,
+ template_desc->num_fields), GFP_NOFS);
if (!*entry)
return -ENOMEM;
@@ -129,15 +135,17 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
{
struct ima_template_entry *entry;
struct inode *inode = file_inode(file);
- struct ima_event_data event_data = {iint, file, filename, NULL, 0,
- cause};
+ struct ima_event_data event_data = { .iint = iint,
+ .file = file,
+ .filename = filename,
+ .violation = cause };
int violation = 1;
int result;
/* can overflow, only indicator */
atomic_long_inc(&ima_htable.violations);
- result = ima_alloc_init_template(&event_data, &entry);
+ result = ima_alloc_init_template(&event_data, &entry, NULL);
if (result < 0) {
result = -ENOMEM;
goto err_out;
@@ -160,11 +168,13 @@ err_out:
* MAY_APPEND)
* @func: caller identifier
* @pcr: pointer filled in if matched measure policy sets pcr=
+ * @template_desc: pointer filled in if matched measure policy sets template=
*
* The policy is defined in terms of keypairs:
* subj=, obj=, type=, func=, mask=, fsmagic=
* subj,obj, and type: are LSM specific.
* func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK
+ * | KEXEC_CMDLINE
* mask: contains the permission mask
* fsmagic: hex value
*
@@ -172,13 +182,15 @@ err_out:
*
*/
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
- int mask, enum ima_hooks func, int *pcr)
+ int mask, enum ima_hooks func, int *pcr,
+ struct ima_template_desc **template_desc)
{
int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
flags &= ima_policy_flag;
- return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
+ return ima_match_policy(inode, cred, secid, func, mask, flags, pcr,
+ template_desc);
}
/*
@@ -193,7 +205,7 @@ int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
*/
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file, void *buf, loff_t size,
- enum hash_algo algo)
+ enum hash_algo algo, struct modsig *modsig)
{
const char *audit_cause = "failed";
struct inode *inode = file_inode(file);
@@ -207,6 +219,14 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
char digest[IMA_MAX_DIGEST_SIZE];
} hash;
+ /*
+ * Always collect the modsig, because IMA might have already collected
+ * the file digest without collecting the modsig in a previous
+ * measurement rule.
+ */
+ if (modsig)
+ ima_collect_modsig(modsig, buf, size);
+
if (iint->flags & IMA_COLLECTED)
goto out;
@@ -273,21 +293,32 @@ out:
void ima_store_measurement(struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len, int pcr)
+ int xattr_len, const struct modsig *modsig, int pcr,
+ struct ima_template_desc *template_desc)
{
static const char op[] = "add_template_measure";
static const char audit_cause[] = "ENOMEM";
int result = -ENOMEM;
struct inode *inode = file_inode(file);
struct ima_template_entry *entry;
- struct ima_event_data event_data = {iint, file, filename, xattr_value,
- xattr_len, NULL};
+ struct ima_event_data event_data = { .iint = iint,
+ .file = file,
+ .filename = filename,
+ .xattr_value = xattr_value,
+ .xattr_len = xattr_len,
+ .modsig = modsig };
int violation = 0;
- if (iint->measured_pcrs & (0x1 << pcr))
+ /*
+ * We still need to store the measurement in the case of MODSIG because
+ * we only have its contents to put in the list at the time of
+ * appraisal, but a file measurement from earlier might already exist in
+ * the measurement list.
+ */
+ if (iint->measured_pcrs & (0x1 << pcr) && !modsig)
return;
- result = ima_alloc_init_template(&event_data, &entry);
+ result = ima_alloc_init_template(&event_data, &entry, template_desc);
if (result < 0) {
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
op, audit_cause, result, 0);
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index f0cd67cab6aa..136ae4e0ee92 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -54,7 +54,7 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
security_task_getsecid(current, &secid);
return ima_match_policy(inode, current_cred(), secid, func, mask,
- IMA_APPRAISE | IMA_HASH, NULL);
+ IMA_APPRAISE | IMA_HASH, NULL, NULL);
}
static int ima_fix_xattr(struct dentry *dentry,
@@ -165,7 +165,8 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
return sig->hash_algo;
break;
case IMA_XATTR_DIGEST_NG:
- ret = xattr_value->digest[0];
+ /* first byte contains algorithm id */
+ ret = xattr_value->data[0];
if (ret < HASH_ALGO__LAST)
return ret;
break;
@@ -173,7 +174,7 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
/* this is for backward compatibility */
if (xattr_len == 21) {
unsigned int zero = 0;
- if (!memcmp(&xattr_value->digest[16], &zero, 4))
+ if (!memcmp(&xattr_value->data[16], &zero, 4))
return HASH_ALGO_MD5;
else
return HASH_ALGO_SHA1;
@@ -199,6 +200,110 @@ int ima_read_xattr(struct dentry *dentry,
}
/*
+ * xattr_verify - verify xattr digest or signature
+ *
+ * Verify whether the hash or signature matches the file contents.
+ *
+ * Return 0 on success, error code otherwise.
+ */
+static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
+ struct evm_ima_xattr_data *xattr_value, int xattr_len,
+ enum integrity_status *status, const char **cause)
+{
+ int rc = -EINVAL, hash_start = 0;
+
+ switch (xattr_value->type) {
+ case IMA_XATTR_DIGEST_NG:
+ /* first byte contains algorithm id */
+ hash_start = 1;
+ /* fall through */
+ case IMA_XATTR_DIGEST:
+ if (iint->flags & IMA_DIGSIG_REQUIRED) {
+ *cause = "IMA-signature-required";
+ *status = INTEGRITY_FAIL;
+ break;
+ }
+ clear_bit(IMA_DIGSIG, &iint->atomic_flags);
+ if (xattr_len - sizeof(xattr_value->type) - hash_start >=
+ iint->ima_hash->length)
+ /*
+ * xattr length may be longer. md5 hash in previous
+ * version occupied 20 bytes in xattr, instead of 16
+ */
+ rc = memcmp(&xattr_value->data[hash_start],
+ iint->ima_hash->digest,
+ iint->ima_hash->length);
+ else
+ rc = -EINVAL;
+ if (rc) {
+ *cause = "invalid-hash";
+ *status = INTEGRITY_FAIL;
+ break;
+ }
+ *status = INTEGRITY_PASS;
+ break;
+ case EVM_IMA_XATTR_DIGSIG:
+ set_bit(IMA_DIGSIG, &iint->atomic_flags);
+ rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
+ (const char *)xattr_value,
+ xattr_len,
+ iint->ima_hash->digest,
+ iint->ima_hash->length);
+ if (rc == -EOPNOTSUPP) {
+ *status = INTEGRITY_UNKNOWN;
+ break;
+ }
+ if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
+ func == KEXEC_KERNEL_CHECK)
+ rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM,
+ (const char *)xattr_value,
+ xattr_len,
+ iint->ima_hash->digest,
+ iint->ima_hash->length);
+ if (rc) {
+ *cause = "invalid-signature";
+ *status = INTEGRITY_FAIL;
+ } else {
+ *status = INTEGRITY_PASS;
+ }
+ break;
+ default:
+ *status = INTEGRITY_UNKNOWN;
+ *cause = "unknown-ima-data";
+ break;
+ }
+
+ return rc;
+}
+
+/*
+ * modsig_verify - verify modsig signature
+ *
+ * Verify whether the signature matches the file contents.
+ *
+ * Return 0 on success, error code otherwise.
+ */
+static int modsig_verify(enum ima_hooks func, const struct modsig *modsig,
+ enum integrity_status *status, const char **cause)
+{
+ int rc;
+
+ rc = integrity_modsig_verify(INTEGRITY_KEYRING_IMA, modsig);
+ if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
+ func == KEXEC_KERNEL_CHECK)
+ rc = integrity_modsig_verify(INTEGRITY_KEYRING_PLATFORM,
+ modsig);
+ if (rc) {
+ *cause = "invalid-signature";
+ *status = INTEGRITY_FAIL;
+ } else {
+ *status = INTEGRITY_PASS;
+ }
+
+ return rc;
+}
+
+/*
* ima_appraise_measurement - appraise file measurement
*
* Call evm_verifyxattr() to verify the integrity of 'security.ima'.
@@ -210,19 +315,22 @@ int ima_appraise_measurement(enum ima_hooks func,
struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
- int xattr_len)
+ int xattr_len, const struct modsig *modsig)
{
static const char op[] = "appraise_data";
const char *cause = "unknown";
struct dentry *dentry = file_dentry(file);
struct inode *inode = d_backing_inode(dentry);
enum integrity_status status = INTEGRITY_UNKNOWN;
- int rc = xattr_len, hash_start = 0;
+ int rc = xattr_len;
+ bool try_modsig = iint->flags & IMA_MODSIG_ALLOWED && modsig;
- if (!(inode->i_opflags & IOP_XATTR))
+ /* If not appraising a modsig, we need an xattr. */
+ if (!(inode->i_opflags & IOP_XATTR) && !try_modsig)
return INTEGRITY_UNKNOWN;
- if (rc <= 0) {
+ /* If reading the xattr failed and there's no modsig, error out. */
+ if (rc <= 0 && !try_modsig) {
if (rc && rc != -ENODATA)
goto out;
@@ -245,6 +353,10 @@ int ima_appraise_measurement(enum ima_hooks func,
case INTEGRITY_UNKNOWN:
break;
case INTEGRITY_NOXATTRS: /* No EVM protected xattrs. */
+ /* It's fine not to have xattrs when using a modsig. */
+ if (try_modsig)
+ break;
+ /* fall through */
case INTEGRITY_NOLABEL: /* No security.evm xattr. */
cause = "missing-HMAC";
goto out;
@@ -255,65 +367,18 @@ int ima_appraise_measurement(enum ima_hooks func,
WARN_ONCE(true, "Unexpected integrity status %d\n", status);
}
- switch (xattr_value->type) {
- case IMA_XATTR_DIGEST_NG:
- /* first byte contains algorithm id */
- hash_start = 1;
- /* fall through */
- case IMA_XATTR_DIGEST:
- if (iint->flags & IMA_DIGSIG_REQUIRED) {
- cause = "IMA-signature-required";
- status = INTEGRITY_FAIL;
- break;
- }
- clear_bit(IMA_DIGSIG, &iint->atomic_flags);
- if (xattr_len - sizeof(xattr_value->type) - hash_start >=
- iint->ima_hash->length)
- /* xattr length may be longer. md5 hash in previous
- version occupied 20 bytes in xattr, instead of 16
- */
- rc = memcmp(&xattr_value->digest[hash_start],
- iint->ima_hash->digest,
- iint->ima_hash->length);
- else
- rc = -EINVAL;
- if (rc) {
- cause = "invalid-hash";
- status = INTEGRITY_FAIL;
- break;
- }
- status = INTEGRITY_PASS;
- break;
- case EVM_IMA_XATTR_DIGSIG:
- set_bit(IMA_DIGSIG, &iint->atomic_flags);
- rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
- (const char *)xattr_value,
- xattr_len,
- iint->ima_hash->digest,
- iint->ima_hash->length);
- if (rc == -EOPNOTSUPP) {
- status = INTEGRITY_UNKNOWN;
- break;
- }
- if (IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING) && rc &&
- func == KEXEC_KERNEL_CHECK)
- rc = integrity_digsig_verify(INTEGRITY_KEYRING_PLATFORM,
- (const char *)xattr_value,
- xattr_len,
- iint->ima_hash->digest,
- iint->ima_hash->length);
- if (rc) {
- cause = "invalid-signature";
- status = INTEGRITY_FAIL;
- } else {
- status = INTEGRITY_PASS;
- }
- break;
- default:
- status = INTEGRITY_UNKNOWN;
- cause = "unknown-ima-data";
- break;
- }
+ if (xattr_value)
+ rc = xattr_verify(func, iint, xattr_value, xattr_len, &status,
+ &cause);
+
+ /*
+ * If we have a modsig and either no imasig or the imasig's key isn't
+ * known, then try verifying the modsig.
+ */
+ if (try_modsig &&
+ (!xattr_value || xattr_value->type == IMA_XATTR_DIGEST_NG ||
+ rc == -ENOKEY))
+ rc = modsig_verify(func, modsig, &status, &cause);
out:
/*
@@ -331,7 +396,7 @@ out:
op, cause, rc, 0);
} else if (status != INTEGRITY_PASS) {
/* Fix mode, but don't replace file signatures. */
- if ((ima_appraise & IMA_APPRAISE_FIX) &&
+ if ((ima_appraise & IMA_APPRAISE_FIX) && !try_modsig &&
(!xattr_value ||
xattr_value->type != EVM_IMA_XATTR_DIGSIG)) {
if (!ima_fix_xattr(dentry, iint))
@@ -370,7 +435,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
!(iint->flags & IMA_HASH))
return;
- rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo);
+ rc = ima_collect_measurement(iint, file, NULL, 0, ima_hash_algo, NULL);
if (rc < 0)
return;
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index d4c7b8e1b083..73044fc6a952 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -268,8 +268,16 @@ static int ima_calc_file_hash_atfm(struct file *file,
rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
rc = integrity_kernel_read(file, offset, rbuf[active],
rbuf_len);
- if (rc != rbuf_len)
+ if (rc != rbuf_len) {
+ if (rc >= 0)
+ rc = -EINVAL;
+ /*
+ * Forward current rc, do not overwrite with return value
+ * from ahash_wait()
+ */
+ ahash_wait(ahash_rc, &wait);
goto out3;
+ }
if (rbuf[1] && offset) {
/* Using two buffers, and it is not the first
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 1e47c1026471..5d55ade5f3b9 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -45,8 +45,8 @@ static int __init ima_add_boot_aggregate(void)
const char *audit_cause = "ENOMEM";
struct ima_template_entry *entry;
struct integrity_iint_cache tmp_iint, *iint = &tmp_iint;
- struct ima_event_data event_data = {iint, NULL, boot_aggregate_name,
- NULL, 0, NULL};
+ struct ima_event_data event_data = { .iint = iint,
+ .filename = boot_aggregate_name };
int result = -ENOMEM;
int violation = 0;
struct {
@@ -68,7 +68,7 @@ static int __init ima_add_boot_aggregate(void)
}
}
- result = ima_alloc_init_template(&event_data, &entry);
+ result = ima_alloc_init_template(&event_data, &entry, NULL);
if (result < 0) {
audit_cause = "alloc_entry";
goto err_out;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 1747bc7bcb60..60027c643ecd 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -39,6 +39,10 @@ int ima_appraise;
int ima_hash_algo = HASH_ALGO_SHA1;
static int hash_setup_done;
+static struct notifier_block ima_lsm_policy_notifier = {
+ .notifier_call = ima_lsm_policy_change,
+};
+
static int __init hash_setup(char *str)
{
struct ima_template_desc *template_desc = ima_template_desc_current();
@@ -68,6 +72,27 @@ out:
}
__setup("ima_hash=", hash_setup);
+/* Prevent mmap'ing a file execute that is already mmap'ed write */
+static int mmap_violation_check(enum ima_hooks func, struct file *file,
+ char **pathbuf, const char **pathname,
+ char *filename)
+{
+ struct inode *inode;
+ int rc = 0;
+
+ if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) {
+ rc = -ETXTBSY;
+ inode = file_inode(file);
+
+ if (!*pathbuf) /* ima_rdwr_violation possibly pre-fetched */
+ *pathname = ima_d_path(&file->f_path, pathbuf,
+ filename);
+ integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, *pathname,
+ "mmap_file", "mmapped_writers", rc, 0);
+ }
+ return rc;
+}
+
/*
* ima_rdwr_violation_check
*
@@ -170,13 +195,14 @@ static int process_measurement(struct file *file, const struct cred *cred,
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint = NULL;
- struct ima_template_desc *template_desc;
+ struct ima_template_desc *template_desc = NULL;
char *pathbuf = NULL;
char filename[NAME_MAX];
const char *pathname = NULL;
int rc = 0, action, must_appraise = 0;
int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
struct evm_ima_xattr_data *xattr_value = NULL;
+ struct modsig *modsig = NULL;
int xattr_len = 0;
bool violation_check;
enum hash_algo hash_algo;
@@ -188,7 +214,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
* bitmask based on the appraise/audit/measurement policy.
* Included is the appraise submask.
*/
- action = ima_get_action(inode, cred, secid, mask, func, &pcr);
+ action = ima_get_action(inode, cred, secid, mask, func, &pcr,
+ &template_desc);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
if (!action && !violation_check)
@@ -266,20 +293,37 @@ static int process_measurement(struct file *file, const struct cred *cred,
/* Nothing to do, just return existing appraised status */
if (!action) {
- if (must_appraise)
- rc = ima_get_cache_status(iint, func);
+ if (must_appraise) {
+ rc = mmap_violation_check(func, file, &pathbuf,
+ &pathname, filename);
+ if (!rc)
+ rc = ima_get_cache_status(iint, func);
+ }
goto out_locked;
}
- template_desc = ima_template_desc_current();
if ((action & IMA_APPRAISE_SUBMASK) ||
- strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
+ strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) {
/* read 'security.ima' */
xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
+ /*
+ * Read the appended modsig if allowed by the policy, and allow
+ * an additional measurement list entry, if needed, based on the
+ * template format and whether the file was already measured.
+ */
+ if (iint->flags & IMA_MODSIG_ALLOWED) {
+ rc = ima_read_modsig(func, buf, size, &modsig);
+
+ if (!rc && ima_template_has_modsig(template_desc) &&
+ iint->flags & IMA_MEASURED)
+ action |= IMA_MEASURE;
+ }
+ }
+
hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
- rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
+ rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
if (rc != 0 && rc != -EBADF && rc != -EINVAL)
goto out_locked;
@@ -288,12 +332,16 @@ static int process_measurement(struct file *file, const struct cred *cred,
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname,
- xattr_value, xattr_len, pcr);
+ 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);
+ xattr_value, xattr_len, modsig);
inode_unlock(inode);
+ if (!rc)
+ rc = mmap_violation_check(func, file, &pathbuf,
+ &pathname, filename);
}
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
@@ -306,6 +354,7 @@ out_locked:
rc = -EACCES;
mutex_unlock(&iint->mutex);
kfree(xattr_value);
+ ima_free_modsig(modsig);
out:
if (pathbuf)
__putname(pathbuf);
@@ -572,6 +621,80 @@ int ima_load_data(enum kernel_load_data_id id)
return 0;
}
+/*
+ * process_buffer_measurement - Measure the buffer to ima log.
+ * @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.
+ *
+ * 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)
+{
+ int ret = 0;
+ struct ima_template_entry *entry = NULL;
+ struct integrity_iint_cache iint = {};
+ struct ima_event_data event_data = {.iint = &iint,
+ .filename = eventname,
+ .buf = buf,
+ .buf_len = size};
+ struct ima_template_desc *template_desc = 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;
+
+ action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr,
+ &template_desc);
+ if (!(action & IMA_MEASURE))
+ return;
+
+ iint.ima_hash = &hash.hdr;
+ iint.ima_hash->algo = ima_hash_algo;
+ iint.ima_hash->length = hash_digest_size[ima_hash_algo];
+
+ ret = ima_calc_buffer_hash(buf, size, iint.ima_hash);
+ if (ret < 0)
+ goto out;
+
+ ret = ima_alloc_init_template(&event_data, &entry, template_desc);
+ if (ret < 0)
+ goto out;
+
+ ret = ima_store_template(entry, violation, NULL, buf, pcr);
+
+ if (ret < 0)
+ ima_free_template_entry(entry);
+
+out:
+ return;
+}
+
+/**
+ * ima_kexec_cmdline - measure kexec cmdline boot args
+ * @buf: pointer to buffer
+ * @size: size of buffer
+ *
+ * Buffers can only be measured, not appraised.
+ */
+void ima_kexec_cmdline(const void *buf, int size)
+{
+ u32 secid;
+
+ if (buf && size != 0) {
+ security_task_getsecid(current, &secid);
+ process_buffer_measurement(buf, size, "kexec-cmdline",
+ current_cred(), secid);
+ }
+}
+
static int __init init_ima(void)
{
int error;
@@ -589,6 +712,10 @@ static int __init init_ima(void)
error = ima_init();
}
+ error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier);
+ if (error)
+ pr_warn("Couldn't register LSM notifier, error %d\n", error);
+
if (!error)
ima_update_policy_flag();
diff --git a/security/integrity/ima/ima_modsig.c b/security/integrity/ima/ima_modsig.c
new file mode 100644
index 000000000000..d106885cc495
--- /dev/null
+++ b/security/integrity/ima/ima_modsig.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IMA support for appraising module-style appended signatures.
+ *
+ * Copyright (C) 2019 IBM Corporation
+ *
+ * Author:
+ * Thiago Jung Bauermann <bauerman@linux.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/module_signature.h>
+#include <keys/asymmetric-type.h>
+#include <crypto/pkcs7.h>
+
+#include "ima.h"
+
+struct modsig {
+ struct pkcs7_message *pkcs7_msg;
+
+ enum hash_algo hash_algo;
+
+ /* This digest will go in the 'd-modsig' field of the IMA template. */
+ const u8 *digest;
+ u32 digest_size;
+
+ /*
+ * This is what will go to the measurement list if the template requires
+ * storing the signature.
+ */
+ int raw_pkcs7_len;
+ u8 raw_pkcs7[];
+};
+
+/**
+ * ima_hook_supports_modsig - can the policy allow modsig for this hook?
+ *
+ * modsig is only supported by hooks using ima_post_read_file(), because only
+ * they preload the contents of the file in a buffer. FILE_CHECK does that in
+ * some cases, but not when reached from vfs_open(). POLICY_CHECK can support
+ * it, but it's not useful in practice because it's a text file so deny.
+ */
+bool ima_hook_supports_modsig(enum ima_hooks func)
+{
+ switch (func) {
+ case KEXEC_KERNEL_CHECK:
+ case KEXEC_INITRAMFS_CHECK:
+ case MODULE_CHECK:
+ return true;
+ default:
+ return false;
+ }
+}
+
+/*
+ * ima_read_modsig - Read modsig from buf.
+ *
+ * Return: 0 on success, error code otherwise.
+ */
+int ima_read_modsig(enum ima_hooks func, const void *buf, loff_t buf_len,
+ struct modsig **modsig)
+{
+ const size_t marker_len = strlen(MODULE_SIG_STRING);
+ const struct module_signature *sig;
+ struct modsig *hdr;
+ size_t sig_len;
+ const void *p;
+ int rc;
+
+ if (buf_len <= marker_len + sizeof(*sig))
+ return -ENOENT;
+
+ p = buf + buf_len - marker_len;
+ if (memcmp(p, MODULE_SIG_STRING, marker_len))
+ return -ENOENT;
+
+ buf_len -= marker_len;
+ sig = (const struct module_signature *)(p - sizeof(*sig));
+
+ rc = mod_check_sig(sig, buf_len, func_tokens[func]);
+ if (rc)
+ return rc;
+
+ sig_len = be32_to_cpu(sig->sig_len);
+ buf_len -= sig_len + sizeof(*sig);
+
+ /* Allocate sig_len additional bytes to hold the raw PKCS#7 data. */
+ hdr = kzalloc(sizeof(*hdr) + sig_len, GFP_KERNEL);
+ if (!hdr)
+ return -ENOMEM;
+
+ hdr->pkcs7_msg = pkcs7_parse_message(buf + buf_len, sig_len);
+ if (IS_ERR(hdr->pkcs7_msg)) {
+ rc = PTR_ERR(hdr->pkcs7_msg);
+ kfree(hdr);
+ return rc;
+ }
+
+ memcpy(hdr->raw_pkcs7, buf + buf_len, sig_len);
+ hdr->raw_pkcs7_len = sig_len;
+
+ /* We don't know the hash algorithm yet. */
+ hdr->hash_algo = HASH_ALGO__LAST;
+
+ *modsig = hdr;
+
+ return 0;
+}
+
+/**
+ * ima_collect_modsig - Calculate the file hash without the appended signature.
+ *
+ * Since the modsig is part of the file contents, the hash used in its signature
+ * isn't the same one ordinarily calculated by IMA. Therefore PKCS7 code
+ * calculates a separate one for signature verification.
+ */
+void ima_collect_modsig(struct modsig *modsig, const void *buf, loff_t size)
+{
+ int rc;
+
+ /*
+ * Provide the file contents (minus the appended sig) so that the PKCS7
+ * code can calculate the file hash.
+ */
+ size -= modsig->raw_pkcs7_len + strlen(MODULE_SIG_STRING) +
+ sizeof(struct module_signature);
+ rc = pkcs7_supply_detached_data(modsig->pkcs7_msg, buf, size);
+ if (rc)
+ return;
+
+ /* Ask the PKCS7 code to calculate the file hash. */
+ rc = pkcs7_get_digest(modsig->pkcs7_msg, &modsig->digest,
+ &modsig->digest_size, &modsig->hash_algo);
+}
+
+int ima_modsig_verify(struct key *keyring, const struct modsig *modsig)
+{
+ return verify_pkcs7_message_sig(NULL, 0, modsig->pkcs7_msg, keyring,
+ VERIFYING_MODULE_SIGNATURE, NULL, NULL);
+}
+
+int ima_get_modsig_digest(const struct modsig *modsig, enum hash_algo *algo,
+ const u8 **digest, u32 *digest_size)
+{
+ *algo = modsig->hash_algo;
+ *digest = modsig->digest;
+ *digest_size = modsig->digest_size;
+
+ return 0;
+}
+
+int ima_get_raw_modsig(const struct modsig *modsig, const void **data,
+ u32 *data_len)
+{
+ *data = &modsig->raw_pkcs7;
+ *data_len = modsig->raw_pkcs7_len;
+
+ return 0;
+}
+
+void ima_free_modsig(struct modsig *modsig)
+{
+ if (!modsig)
+ return;
+
+ pkcs7_free_message(modsig->pkcs7_msg);
+ kfree(modsig);
+}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index b8773f05f9da..5380aca2b351 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -6,6 +6,9 @@
* ima_policy.c
* - initialize default measure policy rules
*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/init.h>
#include <linux/list.h>
#include <linux/fs.h>
@@ -76,6 +79,7 @@ struct ima_rule_entry {
int type; /* audit type */
} lsm[MAX_LSM_RULES];
char *fsname;
+ struct ima_template_desc *template;
};
/*
@@ -195,7 +199,7 @@ static struct ima_rule_entry secure_boot_rules[] __ro_after_init = {
};
/* An array of architecture specific rules */
-struct ima_rule_entry *arch_policy_entry __ro_after_init;
+static struct ima_rule_entry *arch_policy_entry __ro_after_init;
static LIST_HEAD(ima_default_rules);
static LIST_HEAD(ima_policy_rules);
@@ -245,31 +249,113 @@ static int __init default_appraise_policy_setup(char *str)
}
__setup("ima_appraise_tcb", default_appraise_policy_setup);
+static void ima_lsm_free_rule(struct ima_rule_entry *entry)
+{
+ int i;
+
+ for (i = 0; i < MAX_LSM_RULES; i++) {
+ kfree(entry->lsm[i].rule);
+ kfree(entry->lsm[i].args_p);
+ }
+ kfree(entry);
+}
+
+static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
+{
+ struct ima_rule_entry *nentry;
+ int i, result;
+
+ nentry = kmalloc(sizeof(*nentry), GFP_KERNEL);
+ if (!nentry)
+ return NULL;
+
+ /*
+ * Immutable elements are copied over as pointers and data; only
+ * lsm rules can change
+ */
+ memcpy(nentry, entry, sizeof(*nentry));
+ memset(nentry->lsm, 0, FIELD_SIZEOF(struct ima_rule_entry, lsm));
+
+ for (i = 0; i < MAX_LSM_RULES; i++) {
+ if (!entry->lsm[i].rule)
+ continue;
+
+ nentry->lsm[i].type = entry->lsm[i].type;
+ nentry->lsm[i].args_p = kstrdup(entry->lsm[i].args_p,
+ GFP_KERNEL);
+ if (!nentry->lsm[i].args_p)
+ goto out_err;
+
+ result = security_filter_rule_init(nentry->lsm[i].type,
+ Audit_equal,
+ nentry->lsm[i].args_p,
+ &nentry->lsm[i].rule);
+ if (result == -EINVAL)
+ pr_warn("ima: rule for LSM \'%d\' is undefined\n",
+ entry->lsm[i].type);
+ }
+ return nentry;
+
+out_err:
+ ima_lsm_free_rule(nentry);
+ return NULL;
+}
+
+static int ima_lsm_update_rule(struct ima_rule_entry *entry)
+{
+ struct ima_rule_entry *nentry;
+
+ nentry = ima_lsm_copy_rule(entry);
+ if (!nentry)
+ return -ENOMEM;
+
+ list_replace_rcu(&entry->list, &nentry->list);
+ synchronize_rcu();
+ ima_lsm_free_rule(entry);
+
+ return 0;
+}
+
/*
* The LSM policy can be reloaded, leaving the IMA LSM based rules referring
* to the old, stale LSM policy. Update the IMA LSM based rules to reflect
- * the reloaded LSM policy. We assume the rules still exist; and BUG_ON() if
- * they don't.
+ * the reloaded LSM policy.
*/
static void ima_lsm_update_rules(void)
{
- struct ima_rule_entry *entry;
- int result;
- int i;
+ struct ima_rule_entry *entry, *e;
+ int i, result, needs_update;
- list_for_each_entry(entry, &ima_policy_rules, list) {
+ list_for_each_entry_safe(entry, e, &ima_policy_rules, list) {
+ needs_update = 0;
for (i = 0; i < MAX_LSM_RULES; i++) {
- if (!entry->lsm[i].rule)
- continue;
- result = security_filter_rule_init(entry->lsm[i].type,
- Audit_equal,
- entry->lsm[i].args_p,
- &entry->lsm[i].rule);
- BUG_ON(!entry->lsm[i].rule);
+ if (entry->lsm[i].rule) {
+ needs_update = 1;
+ break;
+ }
+ }
+ if (!needs_update)
+ continue;
+
+ result = ima_lsm_update_rule(entry);
+ if (result) {
+ pr_err("ima: lsm rule update error %d\n",
+ result);
+ return;
}
}
}
+int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
+ void *lsm_data)
+{
+ if (event != LSM_POLICY_CHANGE)
+ return NOTIFY_DONE;
+
+ ima_lsm_update_rules();
+ return NOTIFY_OK;
+}
+
/**
* ima_match_rules - determine whether an inode matches the measure rule.
* @rule: a pointer to a rule
@@ -287,6 +373,11 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
{
int i;
+ if (func == KEXEC_CMDLINE) {
+ if ((rule->flags & IMA_FUNC) && (rule->func == func))
+ return true;
+ return false;
+ }
if ((rule->flags & IMA_FUNC) &&
(rule->func != func && func != POST_SETATTR))
return false;
@@ -323,11 +414,10 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid;
- int retried = 0;
if (!rule->lsm[i].rule)
continue;
-retry:
+
switch (i) {
case LSM_OBJ_USER:
case LSM_OBJ_ROLE:
@@ -348,11 +438,6 @@ retry:
default:
break;
}
- if ((rc < 0) && (!retried)) {
- retried = 1;
- ima_lsm_update_rules();
- goto retry;
- }
if (!rc)
return false;
}
@@ -393,6 +478,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* @func: IMA hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @pcr: set the pcr to extend
+ * @template_desc: the template that should be used for this rule
*
* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
* conditions.
@@ -402,11 +488,15 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* than writes so ima_match_policy() is classical RCU candidate.
*/
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
- enum ima_hooks func, int mask, int flags, int *pcr)
+ enum ima_hooks func, int mask, int flags, int *pcr,
+ struct ima_template_desc **template_desc)
{
struct ima_rule_entry *entry;
int action = 0, actmask = flags | (flags << 1);
+ if (template_desc)
+ *template_desc = ima_template_desc_current();
+
rcu_read_lock();
list_for_each_entry_rcu(entry, ima_rules, list) {
@@ -426,6 +516,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
action |= IMA_FAIL_UNVERIFIABLE_SIGS;
}
+
if (entry->action & IMA_DO_MASK)
actmask &= ~(entry->action | entry->action << 1);
else
@@ -434,6 +525,9 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
if ((pcr) && (entry->flags & IMA_PCR))
*pcr = entry->pcr;
+ if (template_desc && entry->template)
+ *template_desc = entry->template;
+
if (!actmask)
break;
}
@@ -672,7 +766,7 @@ enum {
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_err
+ Opt_pcr, Opt_template, Opt_err
};
static const match_table_t policy_tokens = {
@@ -706,6 +800,7 @@ static const match_table_t policy_tokens = {
{Opt_appraise_type, "appraise_type=%s"},
{Opt_permit_directio, "permit_directio"},
{Opt_pcr, "pcr=%s"},
+ {Opt_template, "template=%s"},
{Opt_err, NULL}
};
@@ -753,12 +848,45 @@ static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
ima_log_string_op(ab, key, value, NULL);
}
+/*
+ * Validating the appended signature included in the measurement list requires
+ * the file hash calculated without the appended signature (i.e., the 'd-modsig'
+ * field). Therefore, notify the user if they have the 'modsig' field but not
+ * the 'd-modsig' field in the template.
+ */
+static void check_template_modsig(const struct ima_template_desc *template)
+{
+#define MSG "template with 'modsig' field also needs 'd-modsig' field\n"
+ bool has_modsig, has_dmodsig;
+ static bool checked;
+ int i;
+
+ /* We only need to notify the user once. */
+ if (checked)
+ return;
+
+ has_modsig = has_dmodsig = false;
+ for (i = 0; i < template->num_fields; i++) {
+ if (!strcmp(template->fields[i]->field_id, "modsig"))
+ has_modsig = true;
+ else if (!strcmp(template->fields[i]->field_id, "d-modsig"))
+ has_dmodsig = true;
+ }
+
+ if (has_modsig && !has_dmodsig)
+ pr_notice(MSG);
+
+ checked = true;
+#undef MSG
+}
+
static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
{
struct audit_buffer *ab;
char *from;
char *p;
bool uid_token;
+ struct ima_template_desc *template_desc;
int result = 0;
ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
@@ -866,6 +994,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
entry->func = KEXEC_INITRAMFS_CHECK;
else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
entry->func = POLICY_CHECK;
+ else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0)
+ entry->func = KEXEC_CMDLINE;
else
result = -EINVAL;
if (!result)
@@ -1035,6 +1165,10 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
ima_log_string(ab, "appraise_type", args[0].from);
if ((strcmp(args[0].from, "imasig")) == 0)
entry->flags |= IMA_DIGSIG_REQUIRED;
+ else if (ima_hook_supports_modsig(entry->func) &&
+ strcmp(args[0].from, "imasig|modsig") == 0)
+ entry->flags |= IMA_DIGSIG_REQUIRED |
+ IMA_MODSIG_ALLOWED;
else
result = -EINVAL;
break;
@@ -1055,6 +1189,28 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
entry->flags |= IMA_PCR;
break;
+ case Opt_template:
+ ima_log_string(ab, "template", args[0].from);
+ if (entry->action != MEASURE) {
+ result = -EINVAL;
+ break;
+ }
+ template_desc = lookup_template_desc(args[0].from);
+ if (!template_desc || entry->template) {
+ result = -EINVAL;
+ break;
+ }
+
+ /*
+ * template_desc_init_fields() does nothing if
+ * the template is already initialised, so
+ * it's safe to do this unconditionally
+ */
+ template_desc_init_fields(template_desc->fmt,
+ &(template_desc->fields),
+ &(template_desc->num_fields));
+ entry->template = template_desc;
+ break;
case Opt_err:
ima_log_string(ab, "UNKNOWN", p);
result = -EINVAL;
@@ -1066,6 +1222,12 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
else if (entry->action == APPRAISE)
temp_ima_appraise |= ima_appraise_flag(entry->func);
+ if (!result && entry->flags & IMA_MODSIG_ALLOWED) {
+ template_desc = entry->template ? entry->template :
+ ima_template_desc_current();
+ check_template_modsig(template_desc);
+ }
+
audit_log_format(ab, "res=%d", !result);
audit_log_end(ab);
return result;
@@ -1137,6 +1299,12 @@ void ima_delete_rules(void)
}
}
+#define __ima_hook_stringify(str) (#str),
+
+const char *const func_tokens[] = {
+ __ima_hooks(__ima_hook_stringify)
+};
+
#ifdef CONFIG_IMA_READ_POLICY
enum {
mask_exec = 0, mask_write, mask_read, mask_append
@@ -1149,12 +1317,6 @@ static const char *const mask_tokens[] = {
"^MAY_APPEND"
};
-#define __ima_hook_stringify(str) (#str),
-
-static const char *const func_tokens[] = {
- __ima_hooks(__ima_hook_stringify)
-};
-
void *ima_policy_start(struct seq_file *m, loff_t *pos)
{
loff_t l = *pos;
@@ -1330,8 +1492,14 @@ int ima_policy_show(struct seq_file *m, void *v)
}
}
}
- if (entry->flags & IMA_DIGSIG_REQUIRED)
- seq_puts(m, "appraise_type=imasig ");
+ if (entry->template)
+ seq_printf(m, "template=%s ", entry->template->name);
+ if (entry->flags & IMA_DIGSIG_REQUIRED) {
+ if (entry->flags & IMA_MODSIG_ALLOWED)
+ seq_puts(m, "appraise_type=imasig|modsig ");
+ else
+ seq_puts(m, "appraise_type=imasig ");
+ }
if (entry->flags & IMA_PERMIT_DIRECTIO)
seq_puts(m, "permit_directio ");
rcu_read_unlock();
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index f4354c267396..6aa6408603e3 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -22,6 +22,8 @@ static struct ima_template_desc builtin_templates[] = {
{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
{.name = "ima-ng", .fmt = "d-ng|n-ng"},
{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
+ {.name = "ima-buf", .fmt = "d-ng|n-ng|buf"},
+ {.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"},
{.name = "", .fmt = ""}, /* placeholder for a custom format */
};
@@ -39,14 +41,41 @@ static const struct ima_template_field supported_fields[] = {
.field_show = ima_show_template_string},
{.field_id = "sig", .field_init = ima_eventsig_init,
.field_show = ima_show_template_sig},
+ {.field_id = "buf", .field_init = ima_eventbuf_init,
+ .field_show = ima_show_template_buf},
+ {.field_id = "d-modsig", .field_init = ima_eventdigest_modsig_init,
+ .field_show = ima_show_template_digest_ng},
+ {.field_id = "modsig", .field_init = ima_eventmodsig_init,
+ .field_show = ima_show_template_sig},
};
-#define MAX_TEMPLATE_NAME_LEN 15
+
+/*
+ * Used when restoring measurements carried over from a kexec. 'd' and 'n' don't
+ * need to be accounted for since they shouldn't be defined in the same template
+ * description as 'd-ng' and 'n-ng' respectively.
+ */
+#define MAX_TEMPLATE_NAME_LEN sizeof("d-ng|n-ng|sig|buf|d-modisg|modsig")
static struct ima_template_desc *ima_template;
-static struct ima_template_desc *lookup_template_desc(const char *name);
-static int template_desc_init_fields(const char *template_fmt,
- const struct ima_template_field ***fields,
- int *num_fields);
+
+/**
+ * ima_template_has_modsig - Check whether template has modsig-related fields.
+ * @ima_template: IMA template to check.
+ *
+ * Tells whether the given template has fields referencing a file's appended
+ * signature.
+ */
+bool ima_template_has_modsig(const struct ima_template_desc *ima_template)
+{
+ int i;
+
+ for (i = 0; i < ima_template->num_fields; i++)
+ if (!strcmp(ima_template->fields[i]->field_id, "modsig") ||
+ !strcmp(ima_template->fields[i]->field_id, "d-modsig"))
+ return true;
+
+ return false;
+}
static int __init ima_template_setup(char *str)
{
@@ -104,7 +133,7 @@ static int __init ima_template_fmt_setup(char *str)
}
__setup("ima_template_fmt=", ima_template_fmt_setup);
-static struct ima_template_desc *lookup_template_desc(const char *name)
+struct ima_template_desc *lookup_template_desc(const char *name)
{
struct ima_template_desc *template_desc;
int found = 0;
@@ -149,9 +178,9 @@ static int template_fmt_size(const char *template_fmt)
return j + 1;
}
-static int template_desc_init_fields(const char *template_fmt,
- const struct ima_template_field ***fields,
- int *num_fields)
+int template_desc_init_fields(const char *template_fmt,
+ const struct ima_template_field ***fields,
+ int *num_fields)
{
const char *template_fmt_ptr;
const struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
@@ -277,9 +306,8 @@ static int ima_restore_template_data(struct ima_template_desc *template_desc,
int ret = 0;
int i;
- *entry = kzalloc(sizeof(**entry) +
- template_desc->num_fields * sizeof(struct ima_field_data),
- GFP_NOFS);
+ *entry = kzalloc(struct_size(*entry, template_data,
+ template_desc->num_fields), GFP_NOFS);
if (!*entry)
return -ENOMEM;
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 9fe0ef7f91e2..32ae05d88257 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -158,6 +158,12 @@ void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
}
+void ima_show_template_buf(struct seq_file *m, enum ima_show_type show,
+ struct ima_field_data *field_data)
+{
+ ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
+}
+
/**
* ima_parse_buf() - Parses lengths and data from an input buffer
* @bufstartp: Buffer start address.
@@ -219,7 +225,8 @@ int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
return 0;
}
-static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
+static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
+ u8 hash_algo,
struct ima_field_data *field_data)
{
/*
@@ -322,6 +329,41 @@ out:
hash_algo, field_data);
}
+/*
+ * This function writes the digest of the file which is expected to match the
+ * digest contained in the file's appended signature.
+ */
+int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data)
+{
+ enum hash_algo hash_algo;
+ const u8 *cur_digest;
+ u32 cur_digestsize;
+
+ if (!event_data->modsig)
+ return 0;
+
+ if (event_data->violation) {
+ /* Recording a violation. */
+ hash_algo = HASH_ALGO_SHA1;
+ cur_digest = NULL;
+ cur_digestsize = 0;
+ } else {
+ int rc;
+
+ rc = ima_get_modsig_digest(event_data->modsig, &hash_algo,
+ &cur_digest, &cur_digestsize);
+ if (rc)
+ return rc;
+ else if (hash_algo == HASH_ALGO__LAST || cur_digestsize == 0)
+ /* There was some error collecting the digest. */
+ return -EINVAL;
+ }
+
+ return ima_eventdigest_init_common(cur_digest, cur_digestsize,
+ hash_algo, field_data);
+}
+
static int ima_eventname_init_common(struct ima_event_data *event_data,
struct ima_field_data *field_data,
bool size_limit)
@@ -385,3 +427,44 @@ int ima_eventsig_init(struct ima_event_data *event_data,
return ima_write_template_field_data(xattr_value, event_data->xattr_len,
DATA_FMT_HEX, field_data);
}
+
+/*
+ * ima_eventbuf_init - include the buffer(kexec-cmldine) as part of the
+ * template data.
+ */
+int ima_eventbuf_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data)
+{
+ if ((!event_data->buf) || (event_data->buf_len == 0))
+ return 0;
+
+ return ima_write_template_field_data(event_data->buf,
+ event_data->buf_len, DATA_FMT_HEX,
+ field_data);
+}
+
+/*
+ * ima_eventmodsig_init - include the appended file signature as part of the
+ * template data
+ */
+int ima_eventmodsig_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data)
+{
+ const void *data;
+ u32 data_len;
+ int rc;
+
+ if (!event_data->modsig)
+ return 0;
+
+ /*
+ * modsig is a runtime structure containing pointers. Get its raw data
+ * instead.
+ */
+ rc = ima_get_raw_modsig(event_data->modsig, &data, &data_len);
+ if (rc)
+ return rc;
+
+ return ima_write_template_field_data(data, data_len, DATA_FMT_HEX,
+ field_data);
+}
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index e515955456a3..9a88c79a7a61 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -25,6 +25,8 @@ void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
struct ima_field_data *field_data);
void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
struct ima_field_data *field_data);
+void ima_show_template_buf(struct seq_file *m, enum ima_show_type show,
+ struct ima_field_data *field_data);
int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
int maxfields, struct ima_field_data *fields, int *curfields,
unsigned long *len_mask, int enforce_mask, char *bufname);
@@ -34,8 +36,14 @@ int ima_eventname_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
int ima_eventdigest_ng_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
+int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data);
int ima_eventname_ng_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
int ima_eventsig_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
+int ima_eventbuf_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data);
+int ima_eventmodsig_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data);
#endif /* __LINUX_IMA_TEMPLATE_LIB_H */
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 65377848fbc5..d9323d31a3a8 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -31,6 +31,7 @@
#define IMA_NEW_FILE 0x04000000
#define EVM_IMMUTABLE_DIGSIG 0x08000000
#define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000
+#define IMA_MODSIG_ALLOWED 0x20000000
#define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \
IMA_HASH | IMA_APPRAISE_SUBMASK)
@@ -74,6 +75,12 @@ enum evm_ima_xattr_type {
struct evm_ima_xattr_data {
u8 type;
+ u8 data[];
+} __packed;
+
+/* Only used in the EVM HMAC code. */
+struct evm_xattr {
+ struct evm_ima_xattr_data data;
u8 digest[SHA1_DIGEST_SIZE];
} __packed;
@@ -141,10 +148,13 @@ int integrity_kernel_read(struct file *file, loff_t offset,
extern struct dentry *integrity_dir;
+struct modsig;
+
#ifdef CONFIG_INTEGRITY_SIGNATURE
int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
const char *digest, int digestlen);
+int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
int __init integrity_init_keyring(const unsigned int id);
int __init integrity_load_x509(const unsigned int id, const char *path);
@@ -159,6 +169,12 @@ static inline int integrity_digsig_verify(const unsigned int id,
return -EOPNOTSUPP;
}
+static inline int integrity_modsig_verify(unsigned int id,
+ const struct modsig *modsig)
+{
+ return -EOPNOTSUPP;
+}
+
static inline int integrity_init_keyring(const unsigned int id)
{
return 0;
@@ -184,6 +200,16 @@ static inline int asymmetric_verify(struct key *keyring, const char *sig,
}
#endif
+#ifdef CONFIG_IMA_APPRAISE_MODSIG
+int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
+#else
+static inline int ima_modsig_verify(struct key *keyring,
+ const struct modsig *modsig)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
#ifdef CONFIG_IMA_LOAD_X509
void __init ima_load_x509(void);
#else
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 09:52:31 +0000