do_last(): ELOOP failure exit should be done after leaving RCU mode

... or we risk seeing a bogus value of d_is_symlink() there.

Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 5 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 65a0e9d1ea48..9c590e0f66e9 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3211,11 +3211,6 @@ finish_lookup:
         if (unlikely(error))
                 return error;
 
-        if (unlikely(d_is_symlink(path.dentry)) && !(open_flag & O_PATH)) {
-                path_to_nameidata(&path, nd);
-                return -ELOOP;
-        }
-
         if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
                 path_to_nameidata(&path, nd);
         } else {
@@ -3234,6 +3229,10 @@ finish_open:
                 return error;
         }
         audit_inode(nd->name, nd->path.dentry, 0);
+        if (unlikely(d_is_symlink(nd->path.dentry)) && !(open_flag & O_PATH)) {
+                error = -ELOOP;
+                goto out;
+        }
         error = -EISDIR;
         if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
                 goto out;