block: do not pass disk names as format strings
Kees Cook [Wed, 3 Jul 2013 22:01:14 +0000 (15:01 -0700)]
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>

block/genhd.c
drivers/block/nbd.c
drivers/scsi/osd/osd_uld.c

index 20625ee..cdeb527 100644 (file)
@@ -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);
index 037288e..46b35f7 100644 (file)
@@ -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);
index 0fab6b5..9d86947 100644 (file)
@@ -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;