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 6edf228..8bd4ef2 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;
 
 
        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);
 
        /* 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 40a0fcb..4d62fe0 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);
 
 
                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);
                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 d4ed9eb..caac1b2 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;
        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;
        if (error) {
                OSD_ERR("dev_set_name failed => %d\n", error);
                goto err_put_cdev;