[ 07/15] block: do not pass disk names as format strings

[Greg Kroah-Hartman]

3.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Kees Cook <keescook@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 block/genhd.c              |    2 +-
 drivers/block/nbd.c        |    3 ++-
 drivers/scsi/osd/osd_uld.c |    2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

--- a/block/genhd.c
+++ b/block/genhd.c
@@ -512,7 +512,7 @@ static void register_disk(struct gendisk
 
 	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);
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -714,7 +714,8 @@ static int __nbd_ioctl(struct block_devi
 		else
 			blk_queue_flush(nbd->disk->queue, 0);
 
-		thread = kthread_create(nbd_thread, nbd, nbd->disk->disk_name);
+		thread = kthread_create(nbd_thread, nbd, "%s",
+					nbd->disk->disk_name);
 		if (IS_ERR(thread)) {
 			mutex_lock(&nbd->tx_lock);
 			return PTR_ERR(thread);
--- a/drivers/scsi/osd/osd_uld.c
+++ b/drivers/scsi/osd/osd_uld.c
@@ -485,7 +485,7 @@ 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;


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