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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-15 22:54:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-15 22:54:12 -0700
commitf91e654474d413201ae578820fb63f8a811f6c4e (patch)
tree7f32d5757381b3371dbf095510622472c7d3aa43 /security/integrity
parentc715ebeb0303b196f17376f189ae4e168d98b563 (diff)
parent3dd0f18c70d94ca2432c78c5735744429f071b0b (diff)
downloadlinux-stericsson-f91e654474d413201ae578820fb63f8a811f6c4e.tar.gz
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris: "This adds support for EVM signatures based on larger digests, contains a new audit record AUDIT_INTEGRITY_POLICY_RULE to differentiate the IMA policy rules from the IMA-audit messages, addresses two deadlocks due to either loading or searching for crypto algorithms, and cleans up the audit messages" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: EVM: fix return value check in evm_write_xattrs() integrity: prevent deadlock during digsig verification. evm: Allow non-SHA1 digital signatures evm: Don't deadlock if a crypto algorithm is unavailable integrity: silence warning when CONFIG_SECURITYFS is not enabled ima: Differentiate auditing policy rules from "audit" actions ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set ima: Use audit_log_format() rather than audit_log_string() ima: Call audit_log_string() rather than logging it untrusted
Diffstat (limited to 'security/integrity')
-rw-r--r--security/integrity/digsig_asymmetric.c23
-rw-r--r--security/integrity/evm/Kconfig1
-rw-r--r--security/integrity/evm/evm.h10
-rw-r--r--security/integrity/evm/evm_crypto.c50
-rw-r--r--security/integrity/evm/evm_main.c19
-rw-r--r--security/integrity/evm/evm_secfs.c4
-rw-r--r--security/integrity/iint.c9
-rw-r--r--security/integrity/ima/Kconfig1
-rw-r--r--security/integrity/ima/ima_policy.c9
-rw-r--r--security/integrity/integrity.h15
-rw-r--r--security/integrity/integrity_audit.c6
11 files changed, 102 insertions, 45 deletions
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index ab6a029062a1..6dc075144508 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -115,3 +115,26 @@ int asymmetric_verify(struct key *keyring, const char *sig,
pr_debug("%s() = %d\n", __func__, ret);
return ret;
}
+
+/**
+ * integrity_kernel_module_request - prevent crypto-pkcs1pad(rsa,*) requests
+ * @kmod_name: kernel module name
+ *
+ * We have situation, when public_key_verify_signature() in case of RSA
+ * algorithm use alg_name to store internal information in order to
+ * construct an algorithm on the fly, but crypto_larval_lookup() will try
+ * to use alg_name in order to load kernel module with same name.
+ * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules,
+ * we are safe to fail such module request from crypto_larval_lookup().
+ *
+ * In this way we prevent modprobe execution during digsig verification
+ * and avoid possible deadlock if modprobe and/or it's dependencies
+ * also signed with digsig.
+ */
+int integrity_kernel_module_request(char *kmod_name)
+{
+ if (strncmp(kmod_name, "crypto-pkcs1pad(rsa,", 20) == 0)
+ return -EINVAL;
+
+ return 0;
+}
diff --git a/security/integrity/evm/Kconfig b/security/integrity/evm/Kconfig
index d593346d0bba..60221852b26a 100644
--- a/security/integrity/evm/Kconfig
+++ b/security/integrity/evm/Kconfig
@@ -4,6 +4,7 @@ config EVM
select ENCRYPTED_KEYS
select CRYPTO_HMAC
select CRYPTO_SHA1
+ select CRYPTO_HASH_INFO
default n
help
EVM protects a file's security extended attributes against
diff --git a/security/integrity/evm/evm.h b/security/integrity/evm/evm.h
index 1257c3c24723..c3f437f5db10 100644
--- a/security/integrity/evm/evm.h
+++ b/security/integrity/evm/evm.h
@@ -47,6 +47,11 @@ extern struct crypto_shash *hash_tfm;
/* List of EVM protected security xattrs */
extern struct list_head evm_config_xattrnames;
+struct evm_digest {
+ struct ima_digest_data hdr;
+ char digest[IMA_MAX_DIGEST_SIZE];
+} __packed;
+
int evm_init_key(void);
int evm_update_evmxattr(struct dentry *dentry,
const char *req_xattr_name,
@@ -54,10 +59,11 @@ int evm_update_evmxattr(struct dentry *dentry,
size_t req_xattr_value_len);
int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
- size_t req_xattr_value_len, char *digest);
+ size_t req_xattr_value_len, struct evm_digest *data);
int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value,
- size_t req_xattr_value_len, char type, char *digest);
+ size_t req_xattr_value_len, char type,
+ struct evm_digest *data);
int evm_init_hmac(struct inode *inode, const struct xattr *xattr,
char *hmac_val);
int evm_init_secfs(void);
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index b60524310855..8a3905bb02c7 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -21,6 +21,7 @@
#include <linux/evm.h>
#include <keys/encrypted-type.h>
#include <crypto/hash.h>
+#include <crypto/hash_info.h>
#include "evm.h"
#define EVMKEY "evm-key"
@@ -29,7 +30,7 @@ static unsigned char evmkey[MAX_KEY_SIZE];
static int evmkey_len = MAX_KEY_SIZE;
struct crypto_shash *hmac_tfm;
-struct crypto_shash *hash_tfm;
+static struct crypto_shash *evm_tfm[HASH_ALGO__LAST];
static DEFINE_MUTEX(mutex);
@@ -38,7 +39,6 @@ static DEFINE_MUTEX(mutex);
static unsigned long evm_set_key_flags;
static char * const evm_hmac = "hmac(sha1)";
-static char * const evm_hash = "sha1";
/**
* evm_set_key() - set EVM HMAC key from the kernel
@@ -74,10 +74,10 @@ busy:
}
EXPORT_SYMBOL_GPL(evm_set_key);
-static struct shash_desc *init_desc(char type)
+static struct shash_desc *init_desc(char type, uint8_t hash_algo)
{
long rc;
- char *algo;
+ const char *algo;
struct crypto_shash **tfm;
struct shash_desc *desc;
@@ -89,15 +89,16 @@ static struct shash_desc *init_desc(char type)
tfm = &hmac_tfm;
algo = evm_hmac;
} else {
- tfm = &hash_tfm;
- algo = evm_hash;
+ tfm = &evm_tfm[hash_algo];
+ algo = hash_algo_name[hash_algo];
}
if (*tfm == NULL) {
mutex_lock(&mutex);
if (*tfm)
goto out;
- *tfm = crypto_alloc_shash(algo, 0, CRYPTO_ALG_ASYNC);
+ *tfm = crypto_alloc_shash(algo, 0,
+ CRYPTO_ALG_ASYNC | CRYPTO_NOLOAD);
if (IS_ERR(*tfm)) {
rc = PTR_ERR(*tfm);
pr_err("Can not allocate %s (reason: %ld)\n", algo, rc);
@@ -186,10 +187,10 @@ static void hmac_add_misc(struct shash_desc *desc, struct inode *inode,
* each xattr, but attempt to re-use the previously allocated memory.
*/
static int evm_calc_hmac_or_hash(struct dentry *dentry,
- const char *req_xattr_name,
- const char *req_xattr_value,
- size_t req_xattr_value_len,
- char type, char *digest)
+ const char *req_xattr_name,
+ const char *req_xattr_value,
+ size_t req_xattr_value_len,
+ uint8_t type, struct evm_digest *data)
{
struct inode *inode = d_backing_inode(dentry);
struct xattr_list *xattr;
@@ -204,10 +205,12 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
inode->i_sb->s_user_ns != &init_user_ns)
return -EOPNOTSUPP;
- desc = init_desc(type);
+ desc = init_desc(type, data->hdr.algo);
if (IS_ERR(desc))
return PTR_ERR(desc);
+ data->hdr.length = crypto_shash_digestsize(desc->tfm);
+
error = -ENODATA;
list_for_each_entry_rcu(xattr, &evm_config_xattrnames, list) {
bool is_ima = false;
@@ -239,7 +242,7 @@ static int evm_calc_hmac_or_hash(struct dentry *dentry,
if (is_ima)
ima_present = true;
}
- hmac_add_misc(desc, inode, type, digest);
+ hmac_add_misc(desc, inode, type, data->digest);
/* Portable EVM signatures must include an IMA hash */
if (type == EVM_XATTR_PORTABLE_DIGSIG && !ima_present)
@@ -252,18 +255,18 @@ out:
int evm_calc_hmac(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value, size_t req_xattr_value_len,
- char *digest)
+ struct evm_digest *data)
{
return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
- req_xattr_value_len, EVM_XATTR_HMAC, digest);
+ req_xattr_value_len, EVM_XATTR_HMAC, data);
}
int evm_calc_hash(struct dentry *dentry, const char *req_xattr_name,
const char *req_xattr_value, size_t req_xattr_value_len,
- char type, char *digest)
+ char type, struct evm_digest *data)
{
return evm_calc_hmac_or_hash(dentry, req_xattr_name, req_xattr_value,
- req_xattr_value_len, type, digest);
+ req_xattr_value_len, type, data);
}
static int evm_is_immutable(struct dentry *dentry, struct inode *inode)
@@ -303,7 +306,7 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
const char *xattr_value, size_t xattr_value_len)
{
struct inode *inode = d_backing_inode(dentry);
- struct evm_ima_xattr_data xattr_data;
+ struct evm_digest data;
int rc = 0;
/*
@@ -316,13 +319,14 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name,
if (rc)
return -EPERM;
+ data.hdr.algo = HASH_ALGO_SHA1;
rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
- xattr_value_len, xattr_data.digest);
+ xattr_value_len, &data);
if (rc == 0) {
- xattr_data.type = EVM_XATTR_HMAC;
+ data.hdr.xattr.sha1.type = EVM_XATTR_HMAC;
rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_EVM,
- &xattr_data,
- sizeof(xattr_data), 0);
+ &data.hdr.xattr.data[1],
+ SHA1_DIGEST_SIZE + 1, 0);
} else if (rc == -ENODATA && (inode->i_opflags & IOP_XATTR)) {
rc = __vfs_removexattr(dentry, XATTR_NAME_EVM);
}
@@ -334,7 +338,7 @@ int evm_init_hmac(struct inode *inode, const struct xattr *lsm_xattr,
{
struct shash_desc *desc;
- desc = init_desc(EVM_XATTR_HMAC);
+ desc = init_desc(EVM_XATTR_HMAC, HASH_ALGO_SHA1);
if (IS_ERR(desc)) {
pr_info("init_desc failed\n");
return PTR_ERR(desc);
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index f9eff5041e4c..7f3f54d89a6e 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -25,6 +25,7 @@
#include <linux/magic.h>
#include <crypto/hash.h>
+#include <crypto/hash_info.h>
#include <crypto/algapi.h>
#include "evm.h"
@@ -134,8 +135,9 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
struct integrity_iint_cache *iint)
{
struct evm_ima_xattr_data *xattr_data = NULL;
- struct evm_ima_xattr_data calc;
+ struct signature_v2_hdr *hdr;
enum integrity_status evm_status = INTEGRITY_PASS;
+ struct evm_digest digest;
struct inode *inode;
int rc, xattr_len;
@@ -171,25 +173,28 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
evm_status = INTEGRITY_FAIL;
goto out;
}
+
+ digest.hdr.algo = HASH_ALGO_SHA1;
rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
- xattr_value_len, calc.digest);
+ xattr_value_len, &digest);
if (rc)
break;
- rc = crypto_memneq(xattr_data->digest, calc.digest,
- sizeof(calc.digest));
+ rc = crypto_memneq(xattr_data->digest, digest.digest,
+ SHA1_DIGEST_SIZE);
if (rc)
rc = -EINVAL;
break;
case EVM_IMA_XATTR_DIGSIG:
case EVM_XATTR_PORTABLE_DIGSIG:
+ hdr = (struct signature_v2_hdr *)xattr_data;
+ digest.hdr.algo = hdr->hash_algo;
rc = evm_calc_hash(dentry, xattr_name, xattr_value,
- xattr_value_len, xattr_data->type,
- calc.digest);
+ xattr_value_len, xattr_data->type, &digest);
if (rc)
break;
rc = integrity_digsig_verify(INTEGRITY_KEYRING_EVM,
(const char *)xattr_data, xattr_len,
- calc.digest, sizeof(calc.digest));
+ digest.digest, digest.hdr.length);
if (!rc) {
inode = d_backing_inode(dentry);
diff --git a/security/integrity/evm/evm_secfs.c b/security/integrity/evm/evm_secfs.c
index 637eb999e340..77de71b7794c 100644
--- a/security/integrity/evm/evm_secfs.c
+++ b/security/integrity/evm/evm_secfs.c
@@ -193,8 +193,8 @@ static ssize_t evm_write_xattrs(struct file *file, const char __user *buf,
return -E2BIG;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_EVM_XATTR);
- if (IS_ERR(ab))
- return PTR_ERR(ab);
+ if (!ab)
+ return -ENOMEM;
xattr = kmalloc(sizeof(struct xattr_list), GFP_KERNEL);
if (!xattr) {
diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index 149faa81f6f0..5a6810041e5c 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -219,10 +219,13 @@ static int __init integrity_fs_init(void)
{
integrity_dir = securityfs_create_dir("integrity", NULL);
if (IS_ERR(integrity_dir)) {
- pr_err("Unable to create integrity sysfs dir: %ld\n",
- PTR_ERR(integrity_dir));
+ int ret = PTR_ERR(integrity_dir);
+
+ if (ret != -ENODEV)
+ pr_err("Unable to create integrity sysfs dir: %d\n",
+ ret);
integrity_dir = NULL;
- return PTR_ERR(integrity_dir);
+ return ret;
}
return 0;
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 004919d9bf09..13b446328dda 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -12,6 +12,7 @@ config IMA
select TCG_TIS if TCG_TPM && X86
select TCG_CRB if TCG_TPM && ACPI
select TCG_IBMVTPM if TCG_TPM && PPC_PSERIES
+ select INTEGRITY_AUDIT if AUDIT
help
The Trusted Computing Group(TCG) runtime Integrity
Measurement Architecture(IMA) maintains a list of hash
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 1659abb344f9..8c9499867c91 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -657,14 +657,16 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
bool (*rule_operator)(kuid_t, kuid_t))
{
+ if (!ab)
+ return;
+
if (rule_operator == &uid_gt)
audit_log_format(ab, "%s>", key);
else if (rule_operator == &uid_lt)
audit_log_format(ab, "%s<", key);
else
audit_log_format(ab, "%s=", key);
- audit_log_untrustedstring(ab, value);
- audit_log_format(ab, " ");
+ audit_log_format(ab, "%s ", value);
}
static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
{
@@ -679,7 +681,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
bool uid_token;
int result = 0;
- ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
+ ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
+ AUDIT_INTEGRITY_POLICY_RULE);
entry->uid = INVALID_UID;
entry->fowner = INVALID_UID;
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 0bb372eed62a..e60473b13a8d 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -15,6 +15,7 @@
#include <linux/integrity.h>
#include <crypto/sha.h>
#include <linux/key.h>
+#include <linux/audit.h>
/* iint action cache flags */
#define IMA_MEASURE 0x00000001
@@ -199,6 +200,13 @@ static inline void evm_load_x509(void)
void integrity_audit_msg(int audit_msgno, struct inode *inode,
const unsigned char *fname, const char *op,
const char *cause, int result, int info);
+
+static inline struct audit_buffer *
+integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
+{
+ return audit_log_start(ctx, gfp_mask, type);
+}
+
#else
static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
const unsigned char *fname,
@@ -206,4 +214,11 @@ static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
int result, int info)
{
}
+
+static inline struct audit_buffer *
+integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
+{
+ return NULL;
+}
+
#endif
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index ab10a25310a1..82c98f7d217e 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -45,11 +45,7 @@ void integrity_audit_msg(int audit_msgno, struct inode *inode,
from_kuid(&init_user_ns, audit_get_loginuid(current)),
audit_get_sessionid(current));
audit_log_task_context(ab);
- audit_log_format(ab, " op=");
- audit_log_string(ab, op);
- audit_log_format(ab, " cause=");
- audit_log_string(ab, cause);
- audit_log_format(ab, " comm=");
+ audit_log_format(ab, " op=%s cause=%s comm=", op, cause);
audit_log_untrustedstring(ab, get_task_comm(name, current));
if (fname) {
audit_log_format(ab, " name=");