VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors

copy_tree() can theoretically fail in a case other than ENOMEM, but always
returns NULL which is interpreted by callers as -ENOMEM.  Change it to return
an explicit error.

Also change clone_mnt() for consistency and because union mounts will add new
error cases.

Thanks to Andreas Gruenbacher <agruen@suse.de> for a bug fix.
[AV: folded braino fix by Dan Carpenter]

Original-author: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Valerie Aurora <valerie.aurora@gmail.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 5 deletions

diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 5bf0790497e..3a5ca582ba1 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -595,7 +595,7 @@ void audit_trim_trees(void)
 
                 root_mnt = collect_mounts(&path);
                 path_put(&path);
-                if (!root_mnt)
+                if (IS_ERR(root_mnt))
                         goto skip_it;
 
                 spin_lock(&hash_lock);
@@ -669,8 +669,8 @@ int audit_add_tree_rule(struct audit_krule *rule)
                 goto Err;
         mnt = collect_mounts(&path);
         path_put(&path);
-        if (!mnt) {
-                err = -ENOMEM;
+        if (IS_ERR(mnt)) {
+                err = PTR_ERR(mnt);
                 goto Err;
         }
 
@@ -719,8 +719,8 @@ int audit_tag_tree(char *old, char *new)
                 return err;
         tagged = collect_mounts(&path2);
         path_put(&path2);
-        if (!tagged)
-                return -ENOMEM;
+        if (IS_ERR(tagged))
+                return PTR_ERR(tagged);
 
         err = kern_path(old, 0, &path1);
         if (err) {