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From: Ben Hutchings <ben@decadent.org.uk>
To: stable@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-kernel@vger.kernel.org, Petr Matousek <pmatouse@redhat.com>,
	linux-scsi@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
	James Bottomley <JBottomley@parallels.com>
Subject: [PATCH stable 4/4] dm: do not forward ioctls from logical volumes to the underlying device
Date: Tue, 17 Jan 2012 04:07:31 +0000	[thread overview]
Message-ID: <1326773251.2819.173.camel@deadeye> (raw)
In-Reply-To: <1326772723.2819.167.camel@deadeye>

From: Paolo Bonzini <pbonzini@redhat.com>

commit ec8013beddd717d1740cfefb1a9b900deef85462 upstream.

A logical volume can map to just part of underlying physical volume.
In this case, it must be treated like a partition.

Based on a patch from Alasdair G Kergon.

Cc: Alasdair G Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backport to 2.6.32 - drop change to drivers/md/dm-flakey.c]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/md/dm-linear.c |   12 +++++++++++-
 drivers/md/dm-mpath.c  |    6 ++++++
 2 files changed, 17 insertions(+), 1 deletions(-)

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 82f7d6e..7ab302d 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -116,7 +116,17 @@ static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
 			unsigned long arg)
 {
 	struct linear_c *lc = (struct linear_c *) ti->private;
-	return __blkdev_driver_ioctl(lc->dev->bdev, lc->dev->mode, cmd, arg);
+	struct dm_dev *dev = lc->dev;
+	int r = 0;
+
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	if (lc->start ||
+	    ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
+		r = scsi_verify_blk_ioctl(NULL, cmd);
+
+	return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
 }
 
 static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index b03cd39..4ec5fe2 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1464,6 +1464,12 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
 
 	spin_unlock_irqrestore(&m->lock, flags);
 
+	/*
+	 * Only pass ioctls through if the device sizes match exactly.
+	 */
+	if (!r && ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
+		r = scsi_verify_blk_ioctl(NULL, cmd);
+
 	return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 }
 
-- 
1.7.8.2



  parent reply	other threads:[~2012-01-17  4:07 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-12 15:01 [PATCH v2 0/3] possible privilege escalation via SG_IO ioctl (CVE-2011-4127) Paolo Bonzini
2012-01-12 15:01 ` [PATCH v2 1/3] block: add and use scsi_blk_cmd_ioctl Paolo Bonzini
2012-01-12 15:01 ` [PATCH v2 2/3] block: fail SCSI passthrough ioctls on partition devices Paolo Bonzini
2012-01-14 23:43   ` Linus Torvalds
2012-01-16  8:51     ` Paolo Bonzini
2012-01-17  3:58       ` Ben Hutchings
2012-01-17  4:06         ` [PATCH stable 1/4] kernel.h: add printk_ratelimited and pr_<level>_rl Ben Hutchings
2012-01-17  4:06         ` [PATCH stable 2/4] block: add and use scsi_blk_cmd_ioctl Ben Hutchings
2012-01-17  4:07         ` [PATCH stable 3/4] block: fail SCSI passthrough ioctls on partition devices Ben Hutchings
2012-01-17  9:55           ` Paolo Bonzini
2012-01-18  4:47             ` Ben Hutchings
2012-01-18  9:00               ` Paolo Bonzini
2012-01-18 16:04                 ` Ben Hutchings
2012-01-24 12:56                   ` Paolo Bonzini
2012-01-26  0:19                     ` Greg KH
2012-01-26 18:28                       ` Greg KH
2012-01-17  4:07         ` Ben Hutchings [this message]
2012-01-17 20:03     ` [PATCH v2 2/3] " Greg KH
2012-01-12 15:01 ` [PATCH v2 3/3] dm: do not forward ioctls from logical volumes to the underlying device Paolo Bonzini
2012-01-16  1:04 ` [PATCH v2 0/3] possible privilege escalation via SG_IO ioctl (CVE-2011-4127) Douglas Gilbert
2012-01-16  8:54   ` Paolo Bonzini

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