From ee3989464a4c4896ec29f5b1c2aae840fab8b73d Mon Sep 17 00:00:00 2001 From: Neil Brown Date: Mon, 26 Oct 2009 08:59:17 +0100 Subject: block: use after free bug in __blkdev_get commit 960cc0f4fef607baabc2232fbd7cce5368a9dcfd upstream. commit 0762b8bde9729f10f8e6249809660ff2ec3ad735 (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 Acked-by: Tejun Heo Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/block_dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 94dfda24c06e..9d544ea02c0a 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -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) { -- cgit v1.2.3