[PATCH v4 05/10] IMA: Updated IMA policy functions to return keyrings option read from the policy

Lakshmi Ramasubramanian
2019-11-06T19:01:46Z

keyrings option read from the IMA policy needs to be provided to
the callers that determine the action to be performed.

This patch updates ima_get_action() and ima_match_policy() functions
to return the keyrings option specified in the IMA policy.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
security/integrity/ima/ima.h | 6 ++++--
security/integrity/ima/ima_api.c | 8 +++++---
security/integrity/ima/ima_appraise.c | 2 +-
security/integrity/ima/ima_main.c | 5 +++--
security/integrity/ima/ima_policy.c | 7 ++++++-
5 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 7f23405b2718..387829afb9a2 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -208,7 +208,8 @@ 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,
- struct ima_template_desc **template_desc);
+ struct ima_template_desc **template_desc,
+ char **keyrings);
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,
@@ -235,7 +236,8 @@ 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,
- struct ima_template_desc **template_desc);
+ struct ima_template_desc **template_desc,
+ char **keyrings);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flag(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 610759fe63b8..fa2cd71ddf1a 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -169,12 +169,13 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
* @func: caller identifier
* @pcr: pointer filled in if matched measure policy sets pcr=
* @template_desc: pointer filled in if matched measure policy sets template=
+ * @keyrings: pointer filled in if matched measure policy sets keyrings=
*
* 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
+ * | KEXEC_CMDLINE | KEYRING_CHECK
* mask: contains the permission mask
* fsmagic: hex value
*
@@ -183,14 +184,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
*/
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
int mask, enum ima_hooks func, int *pcr,
- struct ima_template_desc **template_desc)
+ struct ima_template_desc **template_desc,
+ char **keyrings)
{
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,
- template_desc);
+ template_desc, keyrings);
}

/*
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 300c8d2943c5..47ad4f56c0a8 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -55,7 +55,7 @@ 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, NULL);
+ IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
}

static int ima_fix_xattr(struct dentry *dentry,
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index a0e233afe876..b6d17f37ba61 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -215,7 +215,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
* Included is the appraise submask.
*/
action = ima_get_action(inode, cred, secid, mask, func, &pcr,
- &template_desc);
+ &template_desc, NULL);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
if (!action && !violation_check)
@@ -647,6 +647,7 @@ void process_buffer_measurement(const void *buf, int size,
.buf = buf,
.buf_len = size};
struct ima_template_desc *template = NULL;
+ char *keyrings = NULL;
struct {
struct ima_digest_data hdr;
char digest[IMA_MAX_DIGEST_SIZE];
@@ -665,7 +666,7 @@ void process_buffer_measurement(const void *buf, int size,
if (func) {
security_task_getsecid(current, &secid);
action = ima_get_action(NULL, current_cred(), secid, 0, func,
- &pcr, &template);
+ &pcr, &template, &keyrings);
if (!(action & IMA_MEASURE))
return;
}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 74a727dc6030..53379a19de43 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -481,6 +481,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* @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
+ * @keyrings: set the keyrings for this rule, if specified
*
* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
* conditions.
@@ -491,7 +492,8 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
*/
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
enum ima_hooks func, int mask, int flags, int *pcr,
- struct ima_template_desc **template_desc)
+ struct ima_template_desc **template_desc,
+ char **keyrings)
{
struct ima_rule_entry *entry;
int action = 0, actmask = flags | (flags << 1);
@@ -527,6 +529,9 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
if ((pcr) && (entry->flags & IMA_PCR))
*pcr = entry->pcr;

+ if ((keyrings) && (entry->flags & IMA_KEYRINGS))
+ *keyrings = entry->keyrings;
+
if (template_desc && entry->template)
*template_desc = entry->template;

--
2.17.1