3 files changed, 56 insertions, 30 deletions

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c2edba8..c7e8db0 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -199,42 +199,59 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
 	struct inode *inode = file_inode(file);
 	const char *filename = file->f_path.dentry->d_name.name;
 	int result = 0;
+	int length;
+	void *tmpbuf;
+	u64 i_version;
 	struct {
 		struct ima_digest_data hdr;
 		char digest[IMA_MAX_DIGEST_SIZE];
 	} hash;
 
-	if (!(iint->flags & IMA_COLLECTED)) {
-		u64 i_version = file_inode(file)->i_version;
+	if (iint->flags & IMA_COLLECTED)
+		goto out;
 
-		if (file->f_flags & O_DIRECT) {
-			audit_cause = "failed(directio)";
-			result = -EACCES;
-			goto out;
-		}
+	/*
+	 * Dectecting file change is based on i_version. On filesystems
+	 * which do not support i_version, support is limited to an initial
+	 * measurement/appraisal/audit.
+	 */
+	i_version = file_inode(file)->i_version;
+	hash.hdr.algo = algo;
 
-		hash.hdr.algo = algo;
-
-		result = (!buf) ?  ima_calc_file_hash(file, &hash.hdr) :
-			ima_calc_buffer_hash(buf, size, &hash.hdr);
-		if (!result) {
-			int length = sizeof(hash.hdr) + hash.hdr.length;
-			void *tmpbuf = krealloc(iint->ima_hash, length,
-						GFP_NOFS);
-			if (tmpbuf) {
-				iint->ima_hash = tmpbuf;
-				memcpy(iint->ima_hash, &hash, length);
-				iint->version = i_version;
-				iint->flags |= IMA_COLLECTED;
-			} else
-				result = -ENOMEM;
-		}
+	/* Initialize hash digest to 0's in case of failure */
+	memset(&hash.digest, 0, sizeof(hash.digest));
+
+	if (buf)
+		result = ima_calc_buffer_hash(buf, size, &hash.hdr);
+	else
+		result = ima_calc_file_hash(file, &hash.hdr);
+
+	if (result && result != -EBADF && result != -EINVAL)
+		goto out;
+
+	length = sizeof(hash.hdr) + hash.hdr.length;
+	tmpbuf = krealloc(iint->ima_hash, length, GFP_NOFS);
+	if (!tmpbuf) {
+		result = -ENOMEM;
+		goto out;
 	}
+
+	iint->ima_hash = tmpbuf;
+	memcpy(iint->ima_hash, &hash, length);
+	iint->version = i_version;
+
+	/* Possibly temporary failure due to type of read (eg. O_DIRECT) */
+	if (!result)
+		iint->flags |= IMA_COLLECTED;
 out:
-	if (result)
+	if (result) {
+		if (file->f_flags & O_DIRECT)
+			audit_cause = "failed(directio)";
+
 		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
 				    filename, "collect_data", audit_cause,
 				    result, 0);
+	}
 	return result;
 }
 
@@ -278,7 +295,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
 	}
 
 	result = ima_store_template(entry, violation, inode, filename, pcr);
-	if (!result || result == -EEXIST) {
+	if ((!result || result == -EEXIST) && !(file->f_flags & O_DIRECT)) {
 		iint->flags |= IMA_MEASURED;
 		iint->measured_pcrs |= (0x1 << pcr);
 	}
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 802d5d2..a856d8c 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -441,6 +441,16 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 	loff_t i_size;
 	int rc;
 
+	/*
+	 * For consistency, fail file's opened with the O_DIRECT flag on
+	 * filesystems mounted with/without DAX option.
+	 */
+	if (file->f_flags & O_DIRECT) {
+		hash->length = hash_digest_size[ima_hash_algo];
+		hash->algo = ima_hash_algo;
+		return -EINVAL;
+	}
+
 	i_size = i_size_read(file_inode(file));
 
 	if (ima_ahash_minsize && i_size >= ima_ahash_minsize) {
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 2aebb79..12738c8 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -235,11 +235,8 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
 	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
 
 	rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
-	if (rc != 0) {
-		if (file->f_flags & O_DIRECT)
-			rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;
+	if (rc != 0 && rc != -EBADF && rc != -EINVAL)
 		goto out_digsig;
-	}
 
 	if (!pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
 		pathname = ima_d_path(&file->f_path, &pathbuf, filename);
@@ -247,12 +244,14 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
 	if (action & IMA_MEASURE)
 		ima_store_measurement(iint, file, pathname,
 				      xattr_value, xattr_len, pcr);
-	if (action & IMA_APPRAISE_SUBMASK)
+	if (rc == 0 && (action & IMA_APPRAISE_SUBMASK))
 		rc = ima_appraise_measurement(func, iint, file, pathname,
 					      xattr_value, xattr_len, opened);
 	if (action & IMA_AUDIT)
 		ima_audit_measurement(iint, pathname);
 
+	if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
+		rc = 0;
 out_digsig:
 	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG) &&
 	     !(iint->flags & IMA_NEW_FILE))