Commit f0fba398 authored Nov 06, 2017 by Colin Ian King Committed by Jens Axboe Nov 10, 2017

block: avoid null pointer dereference on null disk



It is possible that the pointer disk can be null and hence
we can get a null pointer deference when accessing disk->flags.
Add a null pointer check to avoid the dereference.

Detected by CoverityScan, CID#1461133 ("Explicit null dereferenced")

Fixes: 8ddcd653 ("block: introduce GENHD_FL_HIDDEN")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 67f2519f

block/genhd.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -798,7 +798,7 @@ struct gendisk get_gendisk(dev_t devt, int partno)
		spin_unlock_bh(&ext_devt_lock);
		}

		if (unlikely(disk->flags & GENHD_FL_HIDDEN)) {
		if (disk && unlikely(disk->flags & GENHD_FL_HIDDEN)) {
		put_disk(disk);
		disk = NULL;
		}