From d6a300977ac9fd714303049a37e0f5f74ef5e6c9 Mon Sep 17 00:00:00 2001 From: Coly Li Date: Wed, 3 Nov 2021 14:49:17 +0800 Subject: [PATCH] bcache: fix use-after-free problem in bcache_device_free() commit 8468f45091d2866affed6f6a7aecc20779139173 upstream. In bcache_device_free(), pointer disk is referenced still in ida_simple_remove() after blk_cleanup_disk() gets called on this pointer. This may cause a potential panic by use-after-free on the disk pointer. This patch fixes the problem by calling blk_cleanup_disk() after ida_simple_remove(). Fixes: bc70852fd104 ("bcache: convert to blk_alloc_disk/blk_cleanup_disk") Signed-off-by: Coly Li Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Ulf Hansson Cc: stable@vger.kernel.org # v5.14+ Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211103064917.67383-1-colyli@suse.de Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/md/bcache/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index f2874c7..3f72c0f4 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -885,9 +885,9 @@ static void bcache_device_free(struct bcache_device *d) bcache_device_detach(d); if (disk) { - blk_cleanup_disk(disk); ida_simple_remove(&bcache_device_idx, first_minor_to_idx(disk->first_minor)); + blk_cleanup_disk(disk); } bioset_exit(&d->bio_split); -- 2.7.4