cred: Reject inodes with invalid ids in set_create_file_as()

Using INVALID_[UG]ID for the LSM file creation context doesn't make sense, so return an error if the inode passed to set_create_file_as() has an invalid id. Signed-off-by: Seth Forshee <[email protected]> Acked-by: Serge Hallyn <[email protected]> Signed-off-by: Eric W. Biederman <[email protected]>
ericholscher · Jun 30, 2016 · 5f65e5c · 5f65e5c
1 parent 2d7f9e2
commit 5f65e5c
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/kernel/cred.c b/kernel/cred.c
@@ -689,6 +689,8 @@ EXPORT_SYMBOL(set_security_override_from_ctx);
  */
 int set_create_files_as(struct cred *new, struct inode *inode)
 {
+	if (!uid_valid(inode->i_uid) || !gid_valid(inode->i_gid))
+		return -EINVAL;
 	new->fsuid = inode->i_uid;
 	new->fsgid = inode->i_gid;
 	return security_kernel_create_files_as(new, inode);