From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Chinner , Jie Liu , Ben Myers Subject: [PATCH 3.12 024/118] xfs: growfs overruns AGFL buffer on V4 filesystems Date: Wed, 18 Dec 2013 13:11:01 -0800 Message-Id: <20131218211220.162931889@linuxfoundation.org> In-Reply-To: <20131218211219.461663463@linuxfoundation.org> References: <20131218211219.461663463@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Chinner commit f94c44573e7c22860e2c3dfe349c45f72ba35ad3 upstream. This loop in xfs_growfs_data_private() is incorrect for V4 superblocks filesystems: for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++) agfl->agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK); For V4 filesystems, we don't have a agfl header structure, and so XFS_AGFL_SIZE() returns an entire sector's worth of entries, which we then index from an offset into the sector. Hence: buffer overrun. This problem was introduced in 3.10 by commit 77c95bba ("xfs: add CRC checks to the AGFL") which changed the AGFL structure but failed to update the growfs code to handle the different structures. Fix it by using the correct offset into the buffer for both V4 and V5 filesystems. Signed-off-by: Dave Chinner Reviewed-by: Jie Liu Signed-off-by: Ben Myers Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_fsops.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -217,6 +217,8 @@ xfs_growfs_data_private( */ nfree = 0; for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) { + __be32 *agfl_bno; + /* * AG freespace header block */ @@ -276,8 +278,10 @@ xfs_growfs_data_private( agfl->agfl_seqno = cpu_to_be32(agno); uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_uuid); } + + agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, bp); for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++) - agfl->agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK); + agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK); error = xfs_bwrite(bp); xfs_buf_relse(bp);