btrfs: Check name_len before reading btrfs_get_name

In btrfs_get_name, there's btrfs_search_slot and reads name from
inode_ref/root_ref.

Call btrfs_is_name_len_valid in btrfs_get_name.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c
index 87144c9f9593..fa66980726c9 100644
--- a/fs/btrfs/export.c
+++ b/fs/btrfs/export.c
@@ -282,6 +282,11 @@ static int btrfs_get_name(struct dentry *parent, char *name,
                 name_len = btrfs_inode_ref_name_len(leaf, iref);
         }
 
+        ret = btrfs_is_name_len_valid(leaf, path->slots[0], name_ptr, name_len);
+        if (!ret) {
+                btrfs_free_path(path);
+                return -EIO;
+        }
         read_extent_buffer(leaf, name, name_ptr, name_len);
         btrfs_free_path(path);