From 22a94d44bd6876a90630338229da6c0436d46593 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 16 Mar 2011 16:47:17 -0400 Subject: Btrfs: add checks to verify dir items are correct We need to make sure the dir items we get are valid dir items. So any time we try and read one check it with verify_dir_item, which will do various sanity checks to make sure it looks sane. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/dir-item.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'fs/btrfs/dir-item.c') diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index f0cad5ae5be7..02c97ad61b6d 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -377,6 +377,9 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, leaf = path->nodes[0]; dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item); + if (verify_dir_item(root, leaf, dir_item)) + return NULL; + total_len = btrfs_item_size_nr(leaf, path->slots[0]); while (cur < total_len) { this_len = sizeof(*dir_item) + @@ -429,3 +432,35 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans, } return ret; } + +int verify_dir_item(struct btrfs_root *root, + struct extent_buffer *leaf, + struct btrfs_dir_item *dir_item) +{ + u16 namelen = BTRFS_NAME_LEN; + u8 type = btrfs_dir_type(leaf, dir_item); + + if (type >= BTRFS_FT_MAX) { + printk(KERN_CRIT "btrfs: invalid dir item type: %d\n", + (int)type); + return 1; + } + + if (type == BTRFS_FT_XATTR) + namelen = XATTR_NAME_MAX; + + if (btrfs_dir_name_len(leaf, dir_item) > namelen) { + printk(KERN_CRIT "btrfS: invalid dir item name len: %u\n", + (unsigned)btrfs_dir_data_len(leaf, dir_item)); + return 1; + } + + /* BTRFS_MAX_XATTR_SIZE is the same for all dir items */ + if (btrfs_dir_data_len(leaf, dir_item) > BTRFS_MAX_XATTR_SIZE(root)) { + printk(KERN_CRIT "btrfs: invalid dir item data len: %u\n", + (unsigned)btrfs_dir_data_len(leaf, dir_item)); + return 1; + } + + return 0; +} -- cgit v1.2.3-59-g8ed1b