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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[jmm: Backport to 2.6.32]
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 26ada4762fa343ab450afe1ddd89f338e1be4a85..90550ba8347a9332cf8d39660b86a33aa73216a2 100644 (file)
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -655,7 +655,9 @@ 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/fs/partitions/check.c b/fs/partitions/check.c
index 7b685e10cbad8cc9b052cec48737fbf7bf6f7afb..aa90d88118e374b9e1a5adf223063cc2672cd613 100644 (file)
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -476,7 +476,7 @@ 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);