Commit c462ecd6 authored by Andreas Hindborg's avatar Andreas Hindborg Committed by Jens Axboe
Browse files

null_blk: fix validation of block size 

Block size should be between 512 and PAGE_SIZE and be a power of 2. The current
check does not validate this, so update the check.

Without this patch, null_blk would Oops due to a null pointer deref when
loaded with bs=1536 [1].

Link: https://lore.kernel.org/all/87wmn8mocd.fsf@metaspace.dk/



Signed-off-by: default avatarAndreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240603192645.977968-1-nmi@metaspace.dk


[axboe: remove unnecessary braces and != 0 check]
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 0a751df4

drivers/block/null_blk/main.c

+2 −2
Original line number Diff line number Diff line
@@ -1824,8 +1824,8 @@ static int null_validate_conf(struct nullb_device *dev) 
		dev->queue_mode = NULL_Q_MQ;

	}



	dev->blocksize = round_down(dev->blocksize, 512);

	dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);

	if (blk_validate_block_size(dev->blocksize))

		return -EINVAL;



	if (dev->use_per_node_hctx) {

		if (dev->submit_queues != nr_online_nodes)