Merge tag 'integrity-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull integrity update from Mimi Zohar:
 "One doc and one code cleanup, and two bug fixes"

* tag 'integrity-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  ima: Introduce MMAP_CHECK_REQPROT hook
  ima: Align ima_file_mmap() parameters with mmap_file LSM hook
  evm: call dump_security_xattr() in all cases to remove code duplication
  ima: fix ima_delete_rules() kernel-doc warning
  ima: return IMA digest value only when IMA_COLLECTED flag is set
  ima: fix error handling logic when file measurement failed

5 files changed, 42 insertions, 12 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index d8530e722515..c29db699c996 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -190,6 +190,7 @@ static inline unsigned int ima_hash_key(u8 *digest)
 	hook(NONE, none)				\
 	hook(FILE_CHECK, file)				\
 	hook(MMAP_CHECK, mmap)				\
+	hook(MMAP_CHECK_REQPROT, mmap_reqprot)		\
 	hook(BPRM_CHECK, bprm)				\
 	hook(CREDS_CHECK, creds)			\
 	hook(POST_SETATTR, post_setattr)		\
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 9345fd66f5b8..d3662f4acadc 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -179,7 +179,8 @@ err_out:
  *		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 | KEY_CHECK | CRITICAL_DATA
+ *	| KEXEC_CMDLINE | KEY_CHECK | CRITICAL_DATA | SETXATTR_CHECK
+ *	| MMAP_CHECK_REQPROT
  *	mask: contains the permission mask
  *	fsmagic: hex value
  *
@@ -292,7 +293,7 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 		result = ima_calc_file_hash(file, &hash.hdr);
 	}
 
-	if (result == -ENOMEM)
+	if (result && result != -EBADF && result != -EINVAL)
 		goto out;
 
 	length = sizeof(hash.hdr) + hash.hdr.length;
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 555342d337f9..491c1aca0b1c 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -111,6 +111,7 @@ enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
 {
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		return iint->ima_mmap_status;
 	case BPRM_CHECK:
 		return iint->ima_bprm_status;
@@ -131,6 +132,7 @@ static void ima_set_cache_status(struct integrity_iint_cache *iint,
 {
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		iint->ima_mmap_status = status;
 		break;
 	case BPRM_CHECK:
@@ -155,6 +157,7 @@ static void ima_cache_flags(struct integrity_iint_cache *iint,
 {
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		iint->flags |= (IMA_MMAP_APPRAISED | IMA_APPRAISED);
 		break;
 	case BPRM_CHECK:
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 358578267fea..d66a0a36415e 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -89,7 +89,8 @@ static int mmap_violation_check(enum ima_hooks func, struct file *file,
 	struct inode *inode;
 	int rc = 0;
 
-	if ((func == MMAP_CHECK) && mapping_writably_mapped(file->f_mapping)) {
+	if ((func == MMAP_CHECK || func == MMAP_CHECK_REQPROT) &&
+	    mapping_writably_mapped(file->f_mapping)) {
 		rc = -ETXTBSY;
 		inode = file_inode(file);
 
@@ -227,7 +228,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	action = ima_get_action(file_mnt_idmap(file), inode, cred, secid,
 				mask, func, &pcr, &template_desc, NULL,
 				&allowed_algos);
-	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
+	violation_check = ((func == FILE_CHECK || func == MMAP_CHECK ||
+			    func == MMAP_CHECK_REQPROT) &&
 			   (ima_policy_flag & IMA_MEASURE));
 	if (!action && !violation_check)
 		return 0;
@@ -337,7 +339,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
 
 	rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
-	if (rc == -ENOMEM)
+	if (rc != 0 && rc != -EBADF && rc != -EINVAL)
 		goto out_locked;
 
 	if (!pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
@@ -397,7 +399,9 @@ out:
 /**
  * ima_file_mmap - based on policy, collect/store measurement.
  * @file: pointer to the file to be measured (May be NULL)
- * @prot: contains the protection that will be applied by the kernel.
+ * @reqprot: protection requested by the application
+ * @prot: protection that will be applied by the kernel
+ * @flags: operational flags
  *
  * Measure files being mmapped executable based on the ima_must_measure()
  * policy decision.
@@ -405,15 +409,27 @@ out:
  * On success return 0.  On integrity appraisal error, assuming the file
  * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
  */
-int ima_file_mmap(struct file *file, unsigned long prot)
+int ima_file_mmap(struct file *file, unsigned long reqprot,
+		  unsigned long prot, unsigned long flags)
 {
 	u32 secid;
+	int ret;
 
-	if (file && (prot & PROT_EXEC)) {
-		security_current_getsecid_subj(&secid);
+	if (!file)
+		return 0;
+
+	security_current_getsecid_subj(&secid);
+
+	if (reqprot & PROT_EXEC) {
+		ret = process_measurement(file, current_cred(), secid, NULL,
+					  0, MAY_EXEC, MMAP_CHECK_REQPROT);
+		if (ret)
+			return ret;
+	}
+
+	if (prot & PROT_EXEC)
 		return process_measurement(file, current_cred(), secid, NULL,
 					   0, MAY_EXEC, MMAP_CHECK);
-	}
 
 	return 0;
 }
@@ -454,6 +470,10 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot)
 	action = ima_get_action(file_mnt_idmap(vma->vm_file), inode,
 				current_cred(), secid, MAY_EXEC, MMAP_CHECK,
 				&pcr, &template, NULL, NULL);
+	action |= ima_get_action(file_mnt_idmap(vma->vm_file), inode,
+				 current_cred(), secid, MAY_EXEC,
+				 MMAP_CHECK_REQPROT, &pcr, &template, NULL,
+				 NULL);
 
 	/* Is the mmap'ed file in policy? */
 	if (!(action & (IMA_MEASURE | IMA_APPRAISE_SUBMASK)))
@@ -563,7 +583,7 @@ static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf,
 	 * ima_file_hash can be called when ima_collect_measurement has still
 	 * not been called, we might not always have a hash.
 	 */
-	if (!iint->ima_hash) {
+	if (!iint->ima_hash || !(iint->flags & IMA_COLLECTED)) {
 		mutex_unlock(&iint->mutex);
 		return -EOPNOTSUPP;
 	}
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index fc128a6b4abe..3ca8b7348c2e 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -697,6 +697,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
 
 	switch (func) {
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 		return IMA_MMAP_APPRAISE;
 	case BPRM_CHECK:
 		return IMA_BPRM_APPRAISE;
@@ -1266,6 +1267,7 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 	case NONE:
 	case FILE_CHECK:
 	case MMAP_CHECK:
+	case MMAP_CHECK_REQPROT:
 	case BPRM_CHECK:
 	case CREDS_CHECK:
 	case POST_SETATTR:
@@ -1504,6 +1506,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 			else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
 				|| (strcmp(args[0].from, "MMAP_CHECK") == 0))
 				entry->func = MMAP_CHECK;
+			else if ((strcmp(args[0].from, "MMAP_CHECK_REQPROT") == 0))
+				entry->func = MMAP_CHECK_REQPROT;
 			else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
 				entry->func = BPRM_CHECK;
 			else if (strcmp(args[0].from, "CREDS_CHECK") == 0)
@@ -1955,7 +1959,8 @@ ssize_t ima_parse_add_rule(char *rule)
 }
 
 /**
- * ima_delete_rules() called to cleanup invalid in-flight policy.
+ * ima_delete_rules() - called to cleanup invalid in-flight policy.
+ *
  * We don't need locking as we operate on the temp list, which is
  * different from the active one.  There is also only one user of
  * ima_delete_rules() at a time.