From: Kees Cook <keescook@chromium.org>
Date: Wed, 3 Jul 2013 22:01:14 +0000 (-0700)
Subject: block: do not pass disk names as format strings
X-Git-Tag: v3.0.86~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cb065a908d47441cfc660d1cc0a50fceefa0cda0;p=thirdparty%2Fkernel%2Fstable.git

block: do not pass disk names as format strings

commit ffc8b30866879ed9ba62bd0a86fecdbd51cd3d19 upstream.

Disk names may contain arbitrary strings, so they must not be
interpreted as format strings.  It seems that only md allows arbitrary
strings to be used for disk names, but this could allow for a local
memory corruption from uid 0 into ring 0.

CVE-2013-2851

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/block/genhd.c b/block/genhd.c
index d7f7d4e3da372..e9a5220960b83 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -518,7 +518,7 @@ void register_disk(struct gendisk *disk)
 
 	ddev->parent = disk->driverfs_dev;
 
-	dev_set_name(ddev, disk->disk_name);
+	dev_set_name(ddev, "%s", disk->disk_name);
 
 	/* delay uevents, until we scanned partition table */
 	dev_set_uevent_suppress(ddev, 1);
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index f533f3375e247..12a7368577276 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -658,7 +658,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *lo,
 
 		mutex_unlock(&lo->tx_lock);
 
-		thread = kthread_create(nbd_thread, lo, lo->disk->disk_name);
+		thread = kthread_create(nbd_thread, lo, "%s",
+					lo->disk->disk_name);
 		if (IS_ERR(thread)) {
 			mutex_lock(&lo->tx_lock);
 			return PTR_ERR(thread);
diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c
index d4ed9eb526572..caac1b28465ab 100644
--- a/drivers/scsi/osd/osd_uld.c
+++ b/drivers/scsi/osd/osd_uld.c
@@ -465,7 +465,7 @@ static int osd_probe(struct device *dev)
 	oud->class_dev.class = &osd_uld_class;
 	oud->class_dev.parent = dev;
 	oud->class_dev.release = __remove;
-	error = dev_set_name(&oud->class_dev, disk->disk_name);
+	error = dev_set_name(&oud->class_dev, "%s", disk->disk_name);
 	if (error) {
 		OSD_ERR("dev_set_name failed => %d\n", error);
 		goto err_put_cdev;