fs/ntfs3: Fix root inode checking

Separate checking inode->i_op and inode itself.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202302162319.bDJOuyfy-lkp@intel.com/
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index e0f78b306f1538f74bd12b7655de526b7932a9d8..5158dd31fd97f26e0f9c63d8b8c78e53b32b6ac5 100644 (file)
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -1347,12 +1347,21 @@ load_root:
        ref.low = cpu_to_le32(MFT_REC_ROOT);
        ref.seq = cpu_to_le16(MFT_REC_ROOT);
        inode = ntfs_iget5(sb, &ref, &NAME_ROOT);
-       if (IS_ERR(inode) || !inode->i_op) {
+       if (IS_ERR(inode)) {
                err = PTR_ERR(inode);
                ntfs_err(sb, "Failed to load root (%d).", err);
                goto out;
        }
 
+       /*
+        * Final check. Looks like this case should never occurs.
+        */
+       if (!inode->i_op) {
+               err = -EINVAL;
+               ntfs_err(sb, "Failed to load root (%d).", err);
+               goto put_inode_out;
+       }
+
        sb->s_root = d_make_root(inode);
        if (!sb->s_root) {
                err = -ENOMEM;