From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:48469 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936965AbeFSClg (ORCPT ); Mon, 18 Jun 2018 22:41:36 -0400 Received: from discord.disaster.area ([192.168.1.111]) by dastard with esmtp (Exim 4.80) (envelope-from ) id 1fV6aI-0004vc-Gu for linux-xfs@vger.kernel.org; Tue, 19 Jun 2018 12:41:30 +1000 Received: from dave by discord.disaster.area with local (Exim 4.91) (envelope-from ) id 1fV6aI-0005wK-Fb for linux-xfs@vger.kernel.org; Tue, 19 Jun 2018 12:41:30 +1000 From: Dave Chinner Subject: [PATCH 2/2] xfs: More robust inode extent count validation Date: Tue, 19 Jun 2018 12:41:28 +1000 Message-Id: <20180619024128.22669-3-david@fromorbit.com> In-Reply-To: <20180619024128.22669-1-david@fromorbit.com> References: <20180619024128.22669-1-david@fromorbit.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: linux-xfs@vger.kernel.org From: Dave Chinner When the inode is in extent format, it can't have more extents that fit in the inode fork. We don't currenty check this, and so this corruption goes unnoticed by the inode verifiers. This can lead to crashes operating on invalid in-memory structures. Attempts to access such a inode will now error out in the verifier rather than allowing modification operations to proceed. Reported-by: Wen Xu Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_format.h | 3 ++ fs/xfs/libxfs/xfs_inode_buf.c | 74 +++++++++++++++++++++-------------- 2 files changed, 48 insertions(+), 29 deletions(-) diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h index 1c5a8aaf2bfc..1cb298fec274 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -962,6 +962,9 @@ typedef enum xfs_dinode_fmt { XFS_DFORK_DSIZE(dip, mp) : \ XFS_DFORK_ASIZE(dip, mp)) +#define XFS_DFORK_MAXEXT(dip, mp, w) \ + (XFS_DFORK_SIZE(dip, mp, w) / sizeof(xfs_bmbt_rec_t)) + /* * Return pointers to the data or attribute forks. */ diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index d38d724534c4..a41b6e5519e0 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -374,6 +374,45 @@ xfs_log_dinode_to_disk( } } +static xfs_failaddr_t +xfs_dinode_verify_fork( + struct xfs_dinode *dip, + struct xfs_mount *mp, + int whichfork) +{ + uint32_t di_nextents = XFS_DFORK_NEXTENTS(dip, whichfork); + + switch (XFS_DFORK_FORMAT(dip, whichfork)) { + case XFS_DINODE_FMT_LOCAL: + /* + * no local regular files yet + */ + if (whichfork == XFS_DATA_FORK) { + if (S_ISREG(be16_to_cpu(dip->di_mode))) + return __this_address; + if (be64_to_cpu(dip->di_size) > + XFS_DFORK_SIZE(dip, mp, whichfork)) + return __this_address; + } + if (di_nextents) + return __this_address; + /* fall through */ + case XFS_DINODE_FMT_EXTENTS: + if (di_nextents > XFS_DFORK_MAXEXT(dip, mp, whichfork)) + return __this_address; + case XFS_DINODE_FMT_BTREE: + if (whichfork == XFS_ATTR_FORK) + if (di_nextents > MAXAEXTNUM) + return __this_address; + else if (di_nextents > MAXEXTNUM) + return __this_address; + break; + default: + return __this_address; + } + return NULL; +} + xfs_failaddr_t xfs_dinode_verify( struct xfs_mount *mp, @@ -441,24 +480,9 @@ xfs_dinode_verify( case S_IFREG: case S_IFLNK: case S_IFDIR: - switch (dip->di_format) { - case XFS_DINODE_FMT_LOCAL: - /* - * no local regular files yet - */ - if (S_ISREG(mode)) - return __this_address; - if (di_size > XFS_DFORK_DSIZE(dip, mp)) - return __this_address; - if (dip->di_nextents) - return __this_address; - /* fall through */ - case XFS_DINODE_FMT_EXTENTS: - case XFS_DINODE_FMT_BTREE: - break; - default: - return __this_address; - } + fa = xfs_dinode_verify_fork(dip, mp, XFS_DATA_FORK); + if (fa) + return fa; break; case 0: /* Uninitialized inode ok. */ @@ -468,17 +492,9 @@ xfs_dinode_verify( } if (XFS_DFORK_Q(dip)) { - switch (dip->di_aformat) { - case XFS_DINODE_FMT_LOCAL: - if (dip->di_anextents) - return __this_address; - /* fall through */ - case XFS_DINODE_FMT_EXTENTS: - case XFS_DINODE_FMT_BTREE: - break; - default: - return __this_address; - } + fa = xfs_dinode_verify_fork(dip, mp, XFS_ATTR_FORK); + if (fa) + return fa; } else { /* * If there is no fork offset, this may be a freshly-made inode -- 2.17.0