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>

3 files changed, 4 insertions, 3 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 20625eed5511..cdeb5277dfd4 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -512,7 +512,7 @@ static 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 037288e7874d..46b35f7acfde 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -714,7 +714,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
                 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);
diff --git a/drivers/scsi/osd/osd_uld.c b/drivers/scsi/osd/osd_uld.c
index 0fab6b5c7b82..9d86947d67fe 100644
--- 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;