[PATCH v26 13/25] IMA: Change internal interfaces to use lsmblobs

From: Casey Schaufler
Date: Thu May 13 2021 - 16:22:43 EST

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The IMA interfaces ima_get_action() and ima_match_policy()
call LSM functions that use lsmblobs. Change the IMA functions
to pass the lsmblob to be compatible with the LSM functions.

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
Acked-by: Stephen Smalley <sds@xxxxxxxxxxxxx>
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Cc: linux-integrity@xxxxxxxxxxxxxxx
To: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
security/integrity/ima/ima.h | 6 ++---
security/integrity/ima/ima_api.c | 6 ++---
security/integrity/ima/ima_appraise.c | 5 ++--
security/integrity/ima/ima_main.c | 36 +++++++++++----------------
security/integrity/ima/ima_policy.c | 17 ++++++-------
5 files changed, 31 insertions(+), 39 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 55f3bd4f0b01..a6b59fcaf62a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -251,7 +251,7 @@ static inline void ima_process_queued_keys(void) {}

/* LIM API function definitions */
int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, int mask,
+ const struct cred *cred, struct lsmblob *blob, int mask,
enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data);
@@ -282,8 +282,8 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);

/* IMA policy related functions */
int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, enum ima_hooks func,
- int mask, int flags, int *pcr,
+ const struct cred *cred, struct lsmblob *blob,
+ enum ima_hooks func, int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data);
void ima_init_policy(void);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index d8e321cc6936..691f68d478f1 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -165,7 +165,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
* @mnt_userns: user namespace of the mount the inode was found from
* @inode: pointer to the inode associated with the object being validated
* @cred: pointer to credentials structure to validate
- * @secid: secid of the task being validated
+ * @blob: LSM data of the task being validated
* @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
* MAY_APPEND)
* @func: caller identifier
@@ -185,7 +185,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
*
*/
int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, int mask,
+ const struct cred *cred, struct lsmblob *blob, int mask,
enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data)
@@ -194,7 +194,7 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode,

flags &= ima_policy_flag;

- return ima_match_policy(mnt_userns, inode, cred, secid, func, mask,
+ return ima_match_policy(mnt_userns, inode, cred, blob, func, mask,
flags, pcr, template_desc, func_data);
}

diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index f8c7b593175f..b2af72289f00 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -77,10 +77,9 @@ int ima_must_appraise(struct user_namespace *mnt_userns, struct inode *inode,
return 0;

security_task_getsecid_subj(current, &blob);
- /* scaffolding the .secid[0] */
return ima_match_policy(mnt_userns, inode, current_cred(),
- blob.secid[0], func, mask,
- IMA_APPRAISE | IMA_HASH, NULL, NULL, NULL);
+ &blob, func, mask, 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 b3e00340a97c..b63f73d43bd2 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -194,8 +194,8 @@ void ima_file_free(struct file *file)
}

static int process_measurement(struct file *file, const struct cred *cred,
- u32 secid, char *buf, loff_t size, int mask,
- enum ima_hooks func)
+ struct lsmblob *blob, char *buf, loff_t size,
+ int mask, enum ima_hooks func)
{
struct inode *inode = file_inode(file);
struct integrity_iint_cache *iint = NULL;
@@ -218,7 +218,7 @@ 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(file_mnt_user_ns(file), inode, cred, secid,
+ action = ima_get_action(file_mnt_user_ns(file), inode, cred, blob,
mask, func, &pcr, &template_desc, NULL);
violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
(ima_policy_flag & IMA_MEASURE));
@@ -392,8 +392,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)

if (file && (prot & PROT_EXEC)) {
security_task_getsecid_subj(current, &blob);
- /* scaffolding - until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0],
+ return process_measurement(file, current_cred(), &blob,
NULL, 0, MAY_EXEC, MMAP_CHECK);
}

@@ -434,7 +433,7 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
inode = file_inode(vma->vm_file);
/* scaffolding */
action = ima_get_action(file_mnt_user_ns(vma->vm_file), inode,
- current_cred(), blob.secid[0], MAY_EXEC,
+ current_cred(), &blob, MAY_EXEC,
MMAP_CHECK, &pcr, &template, 0);

/* Is the mmap'ed file in policy? */
@@ -473,16 +472,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
struct lsmblob blob;

security_task_getsecid_subj(current, &blob);
- /* scaffolding until process_measurement changes */
- ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
- NULL, 0, MAY_EXEC, BPRM_CHECK);
+ ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
+ MAY_EXEC, BPRM_CHECK);
if (ret)
return ret;

security_cred_getsecid(bprm->cred, &blob);
- /* scaffolding until process_measurement changes */
- return process_measurement(bprm->file, bprm->cred, blob.secid[0],
- NULL, 0, MAY_EXEC, CREDS_CHECK);
+ return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
+ MAY_EXEC, CREDS_CHECK);
}

/**
@@ -500,8 +497,7 @@ int ima_file_check(struct file *file, int mask)
struct lsmblob blob;

security_task_getsecid_subj(current, &blob);
- /* scaffolding until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
+ return process_measurement(file, current_cred(), &blob, NULL, 0,
mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
MAY_APPEND), FILE_CHECK);
}
@@ -698,9 +694,8 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id,
/* Read entire file for all partial reads. */
func = read_idmap[read_id] ?: FILE_CHECK;
security_task_getsecid_subj(current, &blob);
- /* scaffolding - until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0], NULL,
- 0, MAY_READ, func);
+ return process_measurement(file, current_cred(), &blob, NULL, 0,
+ MAY_READ, func);
}

const int read_idmap[READING_MAX_ID] = {
@@ -742,9 +737,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,

func = read_idmap[read_id] ?: FILE_CHECK;
security_task_getsecid_subj(current, &blob);
- /* scaffolding until process_measurement changes */
- return process_measurement(file, current_cred(), blob.secid[0], buf,
- size, MAY_READ, func);
+ return process_measurement(file, current_cred(), &blob, buf, size,
+ MAY_READ, func);
}

/**
@@ -889,7 +883,7 @@ void process_buffer_measurement(struct user_namespace *mnt_userns,
security_task_getsecid_subj(current, &blob);
/* scaffolding */
action = ima_get_action(mnt_userns, inode, current_cred(),
- blob.secid[0], 0, func, &pcr, &template,
+ &blob, 0, func, &pcr, &template,
func_data);
if (!(action & IMA_MEASURE))
return;
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 5ee7629fd782..caacd8bf0462 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -546,7 +546,7 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
* @mnt_userns: user namespace of the mount the inode was found from
* @inode: a pointer to an inode
* @cred: a pointer to a credentials structure for user validation
- * @secid: the secid of the task to be validated
+ * @blob: the lsm data of the task to be validated
* @func: LIM hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @func_data: func specific data, may be NULL
@@ -556,8 +556,8 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule,
static bool ima_match_rules(struct ima_rule_entry *rule,
struct user_namespace *mnt_userns,
struct inode *inode, const struct cred *cred,
- u32 secid, enum ima_hooks func, int mask,
- const char *func_data)
+ struct lsmblob *blob, enum ima_hooks func,
+ int mask, const char *func_data)
{
int i;

@@ -626,8 +626,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule,
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
- lsmblob_init(&lsmdata, secid);
- rc = ima_filter_rule_match(&lsmdata, rule->lsm[i].type,
+ rc = ima_filter_rule_match(blob, rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule);
break;
@@ -671,7 +670,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* @inode: pointer to an inode for which the policy decision is being made
* @cred: pointer to a credentials structure for which the policy decision is
* being made
- * @secid: LSM secid of the task to be validated
+ * @blob: LSM data of the task to be validated
* @func: IMA hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @pcr: set the pcr to extend
@@ -686,8 +685,8 @@ 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 user_namespace *mnt_userns, struct inode *inode,
- const struct cred *cred, u32 secid, enum ima_hooks func,
- int mask, int flags, int *pcr,
+ const struct cred *cred, struct lsmblob *blob,
+ enum ima_hooks func, int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
const char *func_data)
{
@@ -703,7 +702,7 @@ int ima_match_policy(struct user_namespace *mnt_userns, struct inode *inode,
if (!(entry->action & actmask))
continue;

- if (!ima_match_rules(entry, mnt_userns, inode, cred, secid,
+ if (!ima_match_rules(entry, mnt_userns, inode, cred, blob,
func, mask, func_data))
continue;

--
2.29.2

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