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From: Christoph Hellwig <hch@lst.de>
To: stable@vger.kernel.org
Cc: linux-xfs@vger.kernel.org, Amir Goldstein <amir73il@gmail.com>,
	"Darrick J. Wong" <darrick.wong@oracle.com>
Subject: [PATCH 07/19] xfs: sanity check directory inode di_size
Date: Thu,  2 Feb 2017 08:55:59 +0100	[thread overview]
Message-ID: <1486022171-8076-8-git-send-email-hch@lst.de> (raw)
In-Reply-To: <1486022171-8076-1-git-send-email-hch@lst.de>

From: Amir Goldstein <amir73il@gmail.com>

commit 3c6f46eacd876bd723a9bad3c6882714c052fd8e upstream.

This changes fixes an assertion hit when fuzzing on-disk
i_mode values.

The easy case to fix is when changing an empty file
i_mode to S_IFDIR. In this case, xfs_dinode_verify()
detects an illegal zero size for directory and fails
to load the inode structure from disk.

For the case of non empty file whose i_mode is changed
to S_IFDIR, the ASSERT() statement in xfs_dir2_isblock()
is replaced with return -EFSCORRUPTED, to avoid interacting
with corrupted jusk also when XFS_DEBUG is disabled.

Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_dir2.c      | 3 ++-
 fs/xfs/libxfs/xfs_inode_buf.c | 7 +++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c
index 20a96dd..ec326d2 100644
--- a/fs/xfs/libxfs/xfs_dir2.c
+++ b/fs/xfs/libxfs/xfs_dir2.c
@@ -631,7 +631,8 @@ xfs_dir2_isblock(
 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
 		return rval;
 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
-	ASSERT(rval == 0 || args->dp->i_d.di_size == args->geo->blksize);
+	if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
+		return -EFSCORRUPTED;
 	*vp = rval;
 	return 0;
 }
diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index c906e50..977245d 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -386,6 +386,7 @@ xfs_dinode_verify(
 	struct xfs_inode	*ip,
 	struct xfs_dinode	*dip)
 {
+	uint16_t		mode;
 	uint16_t		flags;
 	uint64_t		flags2;
 
@@ -396,8 +397,10 @@ xfs_dinode_verify(
 	if (be64_to_cpu(dip->di_size) & (1ULL << 63))
 		return false;
 
-	/* No zero-length symlinks. */
-	if (S_ISLNK(be16_to_cpu(dip->di_mode)) && dip->di_size == 0)
+	mode = be16_to_cpu(dip->di_mode);
+
+	/* No zero-length symlinks/dirs. */
+	if ((S_ISLNK(mode) || S_ISDIR(mode)) && dip->di_size == 0)
 		return false;
 
 	/* only version 3 or greater inodes are extensively verified here */
-- 
2.1.4


  parent reply	other threads:[~2017-02-02  7:56 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-02  7:55 4.9-stable updates for XFS Christoph Hellwig
2017-02-02  7:55 ` [PATCH 01/19] xfs: bump up reserved blocks in xfs_alloc_set_aside Christoph Hellwig
2017-02-02  7:55 ` [PATCH 02/19] xfs: fix bogus minleft manipulations Christoph Hellwig
2017-02-02  7:55 ` [PATCH 03/19] xfs: adjust allocation length in xfs_alloc_space_available Christoph Hellwig
2017-02-02  7:55 ` [PATCH 04/19] xfs: don't rely on ->total " Christoph Hellwig
2017-02-02  7:55 ` [PATCH 05/19] xfs: don't print warnings when xfs_log_force fails Christoph Hellwig
2017-02-02  7:55 ` [PATCH 06/19] xfs: make the ASSERT() condition likely Christoph Hellwig
2017-02-02  7:55 ` Christoph Hellwig [this message]
2017-02-02  7:56 ` [PATCH 08/19] xfs: add missing include dependencies to xfs_dir2.h Christoph Hellwig
2017-02-02  7:56 ` [PATCH 09/19] xfs: replace xfs_mode_to_ftype table with switch statement Christoph Hellwig
2017-02-02  7:56 ` [PATCH 10/19] xfs: sanity check inode mode when creating new dentry Christoph Hellwig
2017-02-02  7:56 ` [PATCH 11/19] xfs: sanity check inode di_mode Christoph Hellwig
2017-02-02  7:56 ` [PATCH 12/19] xfs: don't wrap ID in xfs_dq_get_next_id Christoph Hellwig
2017-02-02  7:56 ` [PATCH 13/19] xfs: fix xfs_mode_to_ftype() prototype Christoph Hellwig
2017-02-02  7:56 ` [PATCH 14/19] xfs: fix COW writeback race Christoph Hellwig
2017-02-02  7:56 ` [PATCH 15/19] xfs: verify dirblocklog correctly Christoph Hellwig
2017-02-02  7:56 ` [PATCH 16/19] xfs: remove racy hasattr check from attr ops Christoph Hellwig
2017-02-02  7:56 ` [PATCH 17/19] xfs: extsize hints are not unlikely in xfs_bmap_btalloc Christoph Hellwig
2017-02-02  7:56 ` [PATCH 18/19] xfs: clear _XBF_PAGES from buffers when readahead page Christoph Hellwig
2017-02-02  7:56 ` [PATCH 19/19] xfs: fix bmv_count confusion w/ shared extents Christoph Hellwig
2017-02-02 10:18 ` 4.9-stable updates for XFS Greg KH
2017-02-02 16:00 ` Eric Sandeen
2017-02-02 17:34   ` Eric Sandeen

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