From 5a4b653655d554b5f51a5d2252882708c56a6f7e Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Mon, 25 Oct 2021 10:54:25 +0800 Subject: [PATCH] zram: avoid race between zram_remove and disksize_store After resetting device in zram_remove(), disksize_store still may come and allocate resources again before deleting gendisk, fix the race by resetting zram after del_gendisk() returns. At that time, disksize_store can't come any more. Reported-by: Luis Chamberlain Reviewed-by: Luis Chamberlain Signed-off-by: Ming Lei Acked-by: Minchan Kim Link: https://lore.kernel.org/r/20211025025426.2815424-4-ming.lei@redhat.com Signed-off-by: Jens Axboe --- drivers/block/zram/zram_drv.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 13b65eb..2dfa3a3 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2006,6 +2006,13 @@ static int zram_remove(struct zram *zram) /* del_gendisk drains pending reset_store */ WARN_ON_ONCE(claimed && zram->claim); + /* + * disksize_store() may be called in between zram_reset_device() + * and del_gendisk(), so run the last reset to avoid leaking + * anything allocated with disksize_store() + */ + zram_reset_device(zram); + blk_cleanup_disk(zram->disk); kfree(zram); return 0; -- 2.7.4