btrfs: Verify dir_item in replay_xattr_deletes

replay_xattr_deletes calls btrfs_search_slot to get buffer and reads
name.

Call verify_dir_item to check name_len in replay_xattr_deletes to avoid
reading out of boundary.

Signed-off-by: Su Yue <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Author: Su Yue

fs/btrfs/tree-log.c

@@ -2111,6 +2111,7 @@ static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
 			      struct btrfs_path *path,
 			      const u64 ino)
 {
+	struct btrfs_fs_info *fs_info = root->fs_info;
 	struct btrfs_key search_key;
 	struct btrfs_path *log_path;
 	int i;
@@ -2152,6 +2153,12 @@ static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
 			u32 this_len = sizeof(*di) + name_len + data_len;
 			char *name;
 
+			ret = verify_dir_item(fs_info, path->nodes[0],
+					      path->slots[0], di);
+			if (ret) {
+				ret = -EIO;
+				goto out;
+			}
 			name = kmalloc(name_len, GFP_NOFS);
 			if (!name) {
 				ret = -ENOMEM;