From: Su Yue <suy.fnst@cn.fujitsu.com>
Date: Tue, 6 Jun 2017 09:57:07 +0000 (+0800)
Subject: btrfs: Check name_len before in btrfs_del_root_ref
X-Git-Tag: v4.13-rc1~150^2~18
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=64c7b01446f4f1cea3cc4be041001f415ebfdc61;p=karo-tx-linux.git

btrfs: Check name_len before in btrfs_del_root_ref

btrfs_del_root_ref calls btrfs_search_slot and reads name from root_ref.
Call btrfs_is_name_len_valid before memcmp.

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>
---

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 7d6bc308bf43..460db0cb2d07 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -390,6 +390,13 @@ again:
 		WARN_ON(btrfs_root_ref_dirid(leaf, ref) != dirid);
 		WARN_ON(btrfs_root_ref_name_len(leaf, ref) != name_len);
 		ptr = (unsigned long)(ref + 1);
+		ret = btrfs_is_name_len_valid(leaf, path->slots[0], ptr,
+					      name_len);
+		if (!ret) {
+			err = -EIO;
+			goto out;
+		}
+
 		WARN_ON(memcmp_extent_buffer(leaf, name, ptr, name_len));
 		*sequence = btrfs_root_ref_sequence(leaf, ref);