block: use after free bug in __blkdev_get

commit 960cc0f4fef607baabc2232fbd7cce5368a9dcfd upstream.

commit 0762b8bde9
(from 14 months ago) introduced a use-after-free bug which has just
recently started manifesting in my md testing.
I tried git bisect to find out what caused the bug to start
manifesting, and it could have been the recent change to
blk_unregister_queue (48c0d4d4c04) but the results were inconclusive.

This patch certainly fixes my symptoms and looks correct as the two
calls are now in the same order as elsewhere in that function.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Neil Brown
2009-10-26 08:59:17 +01:00
committed by Greg Kroah-Hartman
parent bb969fdc8c
commit ee3989464a

View File

@@ -1243,8 +1243,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
}
} else {
put_disk(disk);
module_put(disk->fops->owner);
put_disk(disk);
disk = NULL;
if (bdev->bd_contains == bdev) {
if (bdev->bd_disk->fops->open) {