From: Tao Ma <boyu.mt@taobao.com>
Date: Thu, 3 Mar 2011 14:58:37 +0000 (+0800)
Subject: ext3: Fix an overflow in ext3_trim_fs.
X-Git-Tag: v2.6.39-rc1~442^2^2~1
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=425fa41072b7dce3d88f392b335e561a770aa6c3;p=pandora-kernel.git

ext3: Fix an overflow in ext3_trim_fs.

In a bs=4096 volume, if we call FITRIM with the following parameter as
fstrim_range(start = 102400, len = 134144000, minlen = 10240), with the
following code:
if (len >= EXT3_BLOCKS_PER_GROUP(sb))
        len -= (EXT3_BLOCKS_PER_GROUP(sb) - first_block);
else
        last_block = first_block + len;

So if len < EXT3_BLOCKS_PER_GROUP while first_block + len >
EXT3_BLOCKS_PER_GROUP, last_block will be set to an overflow value
which exceeds EXT3_BLOCKS_PER_GROUP.

This patch fixes it and adjusts len and last_block accordingly.

Cc: Lukas Czerner <lczerner@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---

Reading git-diff-tree failed