Commit 73a166d9 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

ublk_drv: don't probe partitions if the ubq daemon isn't trusted 



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: 71f28f31 ("ublk_drv: add io_uring based userspace block driver")
Reviewed-by: default avatarZiyangZhang <ZiyangZhang@linux.alibaba.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230106041711.914434-3-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ed878d1c

drivers/block/ublk_drv.c

+9 −0
Original line number Diff line number Diff line
@@ -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: