commit d9ff882b54 upstream.
When powering on a null_blk device that is not already on, the return
value ret that is initialized to be count is reused to check the return
value of null_add_dev(), leading to nullb_device_power_store() to return
null_add_dev() return value (0 on success) instead of "count".
So make sure to set ret to be equal to count when there are no errors.
Fixes: a2db328b08 ("null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20240527043445.235267-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
e0aba0c6d5