[PATCH v2 2/4] ima: Use audit_log_format() rather than audit_log_string()

[Stefan Berger]

Remove the usage of audit_log_string() and replace it with
audit_log_format().

Signed-off-by: Stefan Berger <***@linux.vnet.ibm.com>
Suggested-by: Steve Grubb <***@redhat.com>
Reviewed-by: Mimi Zohar <***@linux.vnet.ibm.com>
Acked-by: Paul Moore <***@paul-moore.com>
---
security/integrity/ima/ima_policy.c | 3 +--
security/integrity/integrity_audit.c | 6 +-----
2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 1d00db19d167..3fcf0935468c 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -634,8 +634,7 @@ static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
audit_log_format(ab, "%s<", key);
else
audit_log_format(ab, "%s=", key);
- audit_log_string(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)
{
diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index 90987d15b6fe..db30763d5525 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=");

[Stefan Berger]

If Integrity is not auditing, IMA shouldn't audit, either.

Signed-off-by: Stefan Berger <***@linux.vnet.ibm.com>
---
security/integrity/ima/Kconfig | 1 +
security/integrity/ima/ima_policy.c | 6 +++++-
security/integrity/integrity.h | 15 +++++++++++++++
3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 6a8f67714c83..94c2151331aa 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 3fcf0935468c..bc99713dfe57 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -628,6 +628,9 @@ 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)
@@ -649,7 +652,8 @@ 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(NULL, GFP_KERNEL,
+ AUDIT_INTEGRITY_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

[Stefan Berger]

The AUDIT_INTEGRITY_RULE is used for auditing IMA policy rules and
the IMA "audit" policy action. This patch defines
AUDIT_INTEGRITY_POLICY_RULE to reflect the IMA policy rules.

Since we defined a new message type we can now also call
audit_log_task_info() for task specific fields. This now produces the
following record when parsing an IMA policy rule:

type=UNKNOWN[1807] msg=audit(1527722337.757:338): action=audit \
func=BPRM_CHECK mask=MAY_EXEC ppid=1613 pid=1657 auid=0 uid=0 \
gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty4 ses=4 \
comm="echo" exe="/usr/bin/echo" \
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 res=1

Signed-off-by: Stefan Berger <***@linux.vnet.ibm.com>
---
include/uapi/linux/audit.h | 1 +
security/integrity/ima/ima_policy.c | 12 +++++++++---
2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index 65d9293f1fb8..cb358551376b 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -148,6 +148,7 @@
#define AUDIT_INTEGRITY_PCR 1804 /* PCR invalidation msgs */
#define AUDIT_INTEGRITY_RULE 1805 /* policy rule */
#define AUDIT_INTEGRITY_EVM_XATTR 1806 /* New EVM-covered xattr */
+#define AUDIT_INTEGRITY_POLICY_RULE 1807 /* IMA policy rules */

#define AUDIT_KERNEL 2000 /* Asynchronous audit record. NOT A REQUEST. */

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index bc99713dfe57..d56857223b73 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -637,7 +637,7 @@ static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
audit_log_format(ab, "%s<", key);
else
audit_log_format(ab, "%s=", key);
- audit_log_format(ab, "%s ", value);
+ audit_log_format(ab, "%s", value);
}
static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
{
@@ -651,9 +651,10 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
char *p;
bool uid_token;
int result = 0;
+ const char *orig_rule = rule;

ab = integrity_audit_log_start(NULL, GFP_KERNEL,
- AUDIT_INTEGRITY_RULE);
+ AUDIT_INTEGRITY_POLICY_RULE);

entry->uid = INVALID_UID;
entry->fowner = INVALID_UID;
@@ -669,6 +670,10 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
break;
if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
continue;
+
+ if (p != orig_rule)
+ audit_log_format(ab, " ");
+
token = match_token(p, policy_tokens, args);
switch (token) {
case Opt_measure:
@@ -953,7 +958,8 @@ 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);

- audit_log_format(ab, "res=%d", !result);
+ audit_log_task_info(ab, current);
+ audit_log_format(ab, " res=%d", !result);
audit_log_end(ab);
return result;
}

[Stefan Berger]

The parameters passed to this logging function are all provided by
a privileged user and therefore we can call audit_log_string()
rather than audit_log_untrustedstring().

Signed-off-by: Stefan Berger <***@linux.vnet.ibm.com>
Suggested-by: Steve Grubb <***@redhat.com>
Acked-by: Paul Moore <***@paul-moore.com>
---
security/integrity/ima/ima_policy.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 8bbc18eb07eb..1d00db19d167 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -634,7 +634,7 @@ static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
audit_log_format(ab, "%s<", key);
else
audit_log_format(ab, "%s=", key);
- audit_log_untrustedstring(ab, value);
+ audit_log_string(ab, value);
audit_log_format(ab, " ");
}
static void ima_log_string(struct audit_buffer *ab, char *key, char *value)