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>
[bwh: Backported to 3.2: adjust device pointer name in nbd.c]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/block/genhd.c b/block/genhd.c
index 6edf2284b276321efed5a01b72685563f05fbe30..8bd4ef247da350075e22ce6a6642814bd7054ff0 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -519,7 +519,7 @@ 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 40a0fcbdd7416a94bbaa93f262593f94ed0e1bd7..4d62fe076b89eaeb518ab1d532c33c7309f37c7f 100644 (file)
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -675,7 +675,8 @@ 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 d4ed9eb526572e07814e167eca89f94d22a3f73a..caac1b28465aba13b3647e8150241f33ee24d908 100644 (file)
--- 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;