@@ -520,15 +520,27 @@ int ima_file_check(struct file *file, int mask)
}
EXPORT_SYMBOL_GPL(ima_file_check);
-static int __ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
+static int __ima_inode_hash(struct inode *inode, struct file *file, char *buf,
+ size_t buf_size)
{
- struct integrity_iint_cache *iint;
- int hash_algo;
+ struct integrity_iint_cache *iint = NULL, tmp_iint;
+ int rc, hash_algo;
- if (!ima_policy_flag)
- return -EOPNOTSUPP;
+ if (ima_policy_flag)
+ iint = integrity_iint_find(inode);
+
+ if (!iint && file) {
+ memset(&tmp_iint, 0, sizeof(tmp_iint));
+ tmp_iint.inode = inode;
+
+ rc = ima_collect_measurement(&tmp_iint, file, NULL, 0,
+ ima_hash_algo, NULL);
+ if (rc < 0)
+ return -EOPNOTSUPP;
+
+ iint = &tmp_iint;
+ }
- iint = integrity_iint_find(inode);
if (!iint)
return -EOPNOTSUPP;
@@ -552,12 +564,14 @@ static int __ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
hash_algo = iint->ima_hash->algo;
mutex_unlock(&iint->mutex);
+ if (iint == &tmp_iint)
+ kfree(iint->ima_hash);
+
return hash_algo;
}
/**
- * ima_file_hash - return the stored measurement if a file has been hashed and
- * is in the iint cache.
+ * ima_file_hash - return a measurement of the file
* @file: pointer to the file
* @buf: buffer in which to store the hash
* @buf_size: length of the buffer
@@ -570,7 +584,7 @@ static int __ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
* The file hash returned is based on the entire file, including the appended
* signature.
*
- * If IMA is disabled or if no measurement is available, return -EOPNOTSUPP.
+ * If the measurement cannot be performed, return -EOPNOTSUPP.
* If the parameters are incorrect, return -EINVAL.
*/
int ima_file_hash(struct file *file, char *buf, size_t buf_size)
@@ -578,7 +592,7 @@ int ima_file_hash(struct file *file, char *buf, size_t buf_size)
if (!file)
return -EINVAL;
- return __ima_inode_hash(file_inode(file), buf, buf_size);
+ return __ima_inode_hash(file_inode(file), file, buf, buf_size);
}
EXPORT_SYMBOL_GPL(ima_file_hash);
@@ -605,7 +619,7 @@ int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size)
if (!inode)
return -EINVAL;
- return __ima_inode_hash(inode, buf, buf_size);
+ return __ima_inode_hash(inode, NULL, buf, buf_size);
}
EXPORT_SYMBOL_GPL(ima_inode_hash);
__ima_inode_hash() checks if a digest has been already calculated by looking for the integrity_iint_cache structure associated to the passed inode. Users of ima_file_hash() (e.g. eBPF) might be interested in obtaining the information without having to setup an IMA policy so that the digest is always available at the time they call this function. Call ima_collect_measurement() in __ima_inode_hash(), if the file descriptor is available (passed by ima_file_hash()), and store the file measurement in a temporary integrity_iint_cache structure. This change does not cause memory usage increase, due to using the temporary integrity_iint_cache structure, and due to freeing the ima_digest_data structure inside integrity_iint_cache before exiting from __ima_inode_hash(). For compatibility reasons, the behavior of ima_inode_hash() remains unchanged. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- security/integrity/ima/ima_main.c | 36 +++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 11 deletions(-)