From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:43814 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752074AbcFWX3i (ORCPT ); Thu, 23 Jun 2016 19:29:38 -0400 From: Liu Bo To: linux-btrfs@vger.kernel.org Cc: dsterba@suse.cz Subject: [PATCH v2] Btrfs: error out if generic_bin_search get invalid arguments Date: Thu, 23 Jun 2016 16:32:45 -0700 Message-Id: <1466724765-27364-1-git-send-email-bo.li.liu@oracle.com> In-Reply-To: <1466645539-27296-1-git-send-email-bo.li.liu@oracle.com> References: <1466645539-27296-1-git-send-email-bo.li.liu@oracle.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: With btrfs-corrupt-block, one can set btree node/leaf's field, if we assign a negative value to node/leaf, we can get various hangs, eg. if extent_root's nritems is -2ULL, then we get stuck in btrfs_read_block_groups() because it has a while loop and btrfs_search_slot() on extent_root will always return the first child. This lets us know what's happening and returns a EINVAL to callers instead of returning the first item. Signed-off-by: Liu Bo --- v2: fix typo of in printed message. fs/btrfs/ctree.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index c49a500..915d224 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1770,6 +1770,14 @@ static noinline int generic_bin_search(struct extent_buffer *eb, unsigned long map_len = 0; int err; + if (low > high) { + btrfs_err(eb->fs_info, + "%s: low (%d) > high (%d) eb %llu owner %llu level %d", + __func__, low, high, eb->start, + btrfs_header_owner(eb), btrfs_header_level(eb)); + return -EINVAL; + } + while (low < high) { mid = (low + high) / 2; offset = p + mid * item_size; -- 2.5.5