Re: [PATCH v3 3/4] ima: Do not audit if CONFIG_INTEGRITY_AUDIT is not set
On Mon, Jun 4, 2018 at 4:54 PM, Stefan Berger
<stefanb(a)linux.vnet.ibm.com> wrote:
If Integrity is not auditing, IMA shouldn't audit, either.
Signed-off-by: Stefan Berger <stefanb(a)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);
There was a lot of confusion here, so this is understandable, but you
should pass "audit_context()"[1] as the first parameter instead of
NULL. Other than that this patch looks fine.
[1] In Linus' tree at the moment you would need to use
current->audit_context, but the audit PR heading to Linus during this
merge window will introduce the "audit_context()" function which is
preferable as we may need to change things around a bit in the near
future.
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
--
2.13.6
--
paul moore
www.paul-moore.com