Commit 5a4b6536 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

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: default avatarLuis Chamberlain <mcgrof@kernel.org>
Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Link: https://lore.kernel.org/r/20211025025426.2815424-4-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8c54499a

drivers/block/zram/zram_drv.c

+7 −0
Original line number Diff line number Diff line
@@ -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;