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 colyli@suse.de Cc: Christoph Hellwig hch@lst.de Cc: Hannes Reinecke hare@suse.de Cc: Ulf Hansson ulf.hansson@linaro.org Cc: stable@vger.kernel.org # v5.14+ --- 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 4a9a65dff95e..86b9e355c583 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);