Commit c37396c1 authored Sep 07, 2008 by Jean Delvare Committed by Mauro Carvalho Chehab Oct 04, 2008

V4L/DVB (8955): bttv: Prevent NULL pointer dereference in radio_open

Fix the following crash in the bttv driver:

BUG: unable to handle kernel NULL pointer dereference at 000000000000036c
IP: [<ffffffffa037860a>] radio_open+0x3a/0x170 [bttv]

This happens because radio_open assumes that all present bttv devices
have a radio function. If a bttv device without radio and one with
radio are installed on the same system, and the one without radio is
registered first, then radio_open checks for the radio device number
of a bttv device that has no radio function, and this breaks. All we
have to do to fix it is to skip bttv devices without a radio function.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

parent c737684b

drivers/media/video/bt8xx/bttv-driver.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3431,7 +3431,7 @@ static int radio_open(struct inode inode, struct file file)
		dprintk("bttv: open minor=%d\n",minor);

		for (i = 0; i < bttv_num; i++) {
		if (bttvs[i].radio_dev->minor == minor) {
		if (bttvs[i].radio_dev && bttvs[i].radio_dev->minor == minor) {
		btv = &bttvs[i];
		break;
		}