Commit d382c5be authored Jun 16, 2021 by Mauro Carvalho Chehab

media: dvb_ca_en50221: avoid speculation from CA slot



As warned by smatch:
	drivers/media/dvb-core/dvb_ca_en50221.c:1392 dvb_ca_en50221_io_do_ioctl() warn: potential spectre issue 'ca->slot_info' [r] (local cap)

There's a potential of using a CAM ioctl for speculation.

The risk here is minimum, as only a small subset of DVB
boards have CI, with a CAM module installed. Also, exploiting
it would require a user capable of starting a DVB application.

There are probably a lot of easier ways to try to exploit.

Yet, it doesn't harm addressing it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

parent 6ef43d27

drivers/media/dvb-core/dvb_ca_en50221.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1386,6 +1386,7 @@ static int dvb_ca_en50221_io_do_ioctl(struct file *file,
		err = -EINVAL;
		goto out_unlock;
		}
		slot = array_index_nospec(slot, ca->slot_count);

		info->type = CA_CI_LINK;
		info->flags = 0;