block: ublk: make sure that block size is set correctly

[ Upstream commit 1d1665279a845d16c93687389e364386e3fe0f38 ]

block size is one very key setting for block layer, and bad block size
could panic kernel easily.

Make sure that block size is set correctly.

Meantime if ublk_validate_params() fails, clear ub->params so that disk
is prevented from being added.

Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
Reported-and-tested-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 22a790d512842fd05744cc16cd061579c22ce8a1..341f490fdbb022383b543f8fce9328fbd0f27c19 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -233,7 +233,7 @@ static int ublk_validate_params(const struct ublk_device *ub)
        if (ub->params.types & UBLK_PARAM_TYPE_BASIC) {
                const struct ublk_param_basic *p = &ub->params.basic;
 
-               if (p->logical_bs_shift > PAGE_SHIFT)
+               if (p->logical_bs_shift > PAGE_SHIFT || p->logical_bs_shift < 9)
                        return -EINVAL;
 
                if (p->logical_bs_shift > p->physical_bs_shift)
@@ -1886,6 +1886,8 @@ static int ublk_ctrl_set_params(struct io_uring_cmd *cmd)
                /* clear all we don't support yet */
                ub->params.types &= UBLK_PARAM_TYPE_ALL;
                ret = ublk_validate_params(ub);
+               if (ret)
+                       ub->params.types = 0;
        }
        mutex_unlock(&ub->mutex);
        ublk_put_device(ub);