ima: Move file-change detection variables into new structure

Move all the variables used for file change detection into a structure
that can be used by IMA and EVM. Implement an inline function for storing
the identification of an inode and one for detecting changes to an inode
based on this new structure.

Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

4 files changed, 10 insertions, 13 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 11d7c0332207..9151b5369cdc 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -175,12 +175,10 @@ struct ima_kexec_hdr {
 /* IMA integrity metadata associated with an inode */
 struct ima_iint_cache {
 	struct mutex mutex;	/* protects: version, flags, digest */
-	u64 version;		/* track inode changes */
+	struct integrity_inode_attributes real_inode;
 	unsigned long flags;
 	unsigned long measured_pcrs;
 	unsigned long atomic_flags;
-	unsigned long real_ino;
-	dev_t real_dev;
 	enum integrity_status ima_file_status:4;
 	enum integrity_status ima_mmap_status:4;
 	enum integrity_status ima_bprm_status:4;
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 3d286de231e1..984e861f6e33 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -305,11 +305,11 @@ int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file,
 
 	iint->ima_hash = tmpbuf;
 	memcpy(iint->ima_hash, &hash, length);
-	iint->version = i_version;
-	if (real_inode != inode) {
-		iint->real_ino = real_inode->i_ino;
-		iint->real_dev = real_inode->i_sb->s_dev;
-	}
+	if (real_inode == inode)
+		iint->real_inode.version = i_version;
+	else
+		integrity_inode_attrs_store(&iint->real_inode, i_version,
+					    real_inode);
 
 	/* Possibly temporary failure due to type of read (eg. O_DIRECT) */
 	if (!result)
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
index e7c9c216c1c6..e23412a2c56b 100644
--- a/security/integrity/ima/ima_iint.c
+++ b/security/integrity/ima/ima_iint.c
@@ -59,7 +59,7 @@ static void ima_iint_init_always(struct ima_iint_cache *iint,
 				 struct inode *inode)
 {
 	iint->ima_hash = NULL;
-	iint->version = 0;
+	iint->real_inode.version = 0;
 	iint->flags = 0UL;
 	iint->atomic_flags = 0UL;
 	iint->ima_file_status = INTEGRITY_UNKNOWN;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index eebf629f192e..4b215d85c14b 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -173,7 +173,7 @@ static void ima_check_last_writer(struct ima_iint_cache *iint,
 				      STATX_CHANGE_COOKIE,
 				      AT_STATX_SYNC_AS_STAT) ||
 		    !(stat.result_mask & STATX_CHANGE_COOKIE) ||
-		    stat.change_cookie != iint->version) {
+		    stat.change_cookie != iint->real_inode.version) {
 			iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
 			iint->measured_pcrs = 0;
 			if (update)
@@ -292,9 +292,8 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	if (real_inode != inode &&
 	    (action & IMA_DO_MASK) && (iint->flags & IMA_DONE_MASK)) {
 		if (!IS_I_VERSION(real_inode) ||
-		    real_inode->i_sb->s_dev != iint->real_dev ||
-		    real_inode->i_ino != iint->real_ino ||
-		    !inode_eq_iversion(real_inode, iint->version)) {
+		    integrity_inode_attrs_changed(&iint->real_inode,
+						  real_inode)) {
 			iint->flags &= ~IMA_DONE_MASK;
 			iint->measured_pcrs = 0;
 		}