From: Ming Lei ming.lei@redhat.com
[ Upstream commit 73a166d9749230d598320fdae3b687cdc0e2e205 ]
If any ubq daemon is unprivileged, the ublk char device is allowed for unprivileged user actually, and we can't trust the current user, so not probe partitions.
Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver") Reviewed-by: ZiyangZhang ZiyangZhang@linux.alibaba.com Signed-off-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20230106041711.914434-3-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/ublk_drv.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index f44b9467720c9..450bd54fd0061 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -159,6 +159,7 @@ struct ublk_device {
struct completion completion; unsigned int nr_queues_ready; + unsigned int nr_privileged_daemon;
/* * Our ubq->daemon may be killed without any notification, so @@ -1178,6 +1179,9 @@ static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq) ubq->ubq_daemon = current; get_task_struct(ubq->ubq_daemon); ub->nr_queues_ready++; + + if (capable(CAP_SYS_ADMIN)) + ub->nr_privileged_daemon++; } if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) complete_all(&ub->completion); @@ -1534,6 +1538,10 @@ static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd) if (ret) goto out_put_disk;
+ /* don't probe partitions if any one ubq daemon is un-trusted */ + if (ub->nr_privileged_daemon != ub->nr_queues_ready) + set_bit(GD_SUPPRESS_PART_SCAN, &disk->state); + get_device(&ub->cdev_dev); ret = add_disk(disk); if (ret) { @@ -1935,6 +1943,7 @@ static int ublk_ctrl_start_recovery(struct io_uring_cmd *cmd) /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */ ub->mm = NULL; ub->nr_queues_ready = 0; + ub->nr_privileged_daemon = 0; init_completion(&ub->completion); ret = 0; out_unlock: