From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:39876 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756778AbcECXfV (ORCPT ); Tue, 3 May 2016 19:35:21 -0400 Date: Tue, 3 May 2016 16:32:34 -0700 From: Liu Bo To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org, vegard.nossum@oracle.com, sterba@suse.com Subject: Re: [PATCH 1/2] Btrfs: add more valid checks for superblock Message-ID: <20160503233234.GE21008@localhost.localdomain> Reply-To: bo.li.liu@oracle.com References: <1462212951-28113-1-git-send-email-bo.li.liu@oracle.com> <9fa04dd7-13c4-6c24-dddc-4521eccea65c@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <9fa04dd7-13c4-6c24-dddc-4521eccea65c@cn.fujitsu.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, May 03, 2016 at 09:02:56AM +0800, Qu Wenruo wrote: > > > Liu Bo wrote on 2016/05/02 11:15 -0700: > >This adds valid checks for super_total_bytes, super_bytes_used and > >super_stripesize. > > > >Reported-by: Vegard Nossum > >Reported-by: Quentin Casasnovas > >Signed-off-by: Liu Bo > >--- > > fs/btrfs/disk-io.c | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > >diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > >index 4e47849..988d03f 100644 > >--- a/fs/btrfs/disk-io.c > >+++ b/fs/btrfs/disk-io.c > >@@ -4120,6 +4120,20 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info, > > * Hint to catch really bogus numbers, bitflips or so, more exact checks are > > * done later > > */ > >+ if (btrfs_super_total_bytes(sb) == 0) { > >+ printk(KERN_ERR "BTRFS: total bytes is zero\n"); > >+ ret = -EINVAL; > >+ } > > Would it be better if using "6 * nodesize"? > > I'd like to use a precious low limit on total bytes, but we don't have such > value, so 6 nodesize would be good. That's good, besides that I'm going to do another check between btrfs_super_total_bytes(sb) and sb->dev_item.total_bytes. Thanks, -liubo > > Thanks, > Qu > > >+ if (btrfs_super_bytes_used(sb) < 6 * btrfs_super_nodesize(sb)) { > >+ printk(KERN_ERR "BTRFS: bytes_used is too small %llu\n", > >+ btrfs_super_bytes_used(sb)); > >+ ret = -EINVAL; > >+ } > >+ if (btrfs_super_stripesize(sb) != 4096) { > >+ printk(KERN_ERR "BTRFS: invalid stripesize %u\n", > >+ btrfs_super_stripesize(sb)); > >+ ret = -EINVAL; > >+ } > > if (btrfs_super_num_devices(sb) > (1UL << 31)) > > printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n", > > btrfs_super_num_devices(sb)); > > > >