[PATCH 5.5 17/23] media: vp7045: do not read uninitialized values if usb transfer fails

Greg Kroah-Hartman
2020-02-03T16:39:12Z

From: Sean Young <sean@mess.org>

commit 26cff637121d8bb866ebd6515c430ac890e6ec80 upstream.

It is not a fatal error if reading the mac address or the remote control
decoder state fails.

Reported-by: syzbot+ec869945d3dde5f33b43@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/usb/dvb-usb/vp7045.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

--- a/drivers/media/usb/dvb-usb/vp7045.c
+++ b/drivers/media/usb/dvb-usb/vp7045.c
@@ -96,10 +96,14 @@ static int vp7045_power_ctrl(struct dvb_

static int vp7045_rc_query(struct dvb_usb_device *d)
{
+ int ret;
u8 key;
- vp7045_usb_op(d,RC_VAL_READ,NULL,0,&key,1,20);

- deb_rc("remote query key: %x %d\n",key,key);
+ ret = vp7045_usb_op(d, RC_VAL_READ, NULL, 0, &key, 1, 20);
+ if (ret)
+ return ret;
+
+ deb_rc("remote query key: %x\n", key);

if (key != 0x44) {
/*
@@ -115,15 +119,18 @@ static int vp7045_rc_query(struct dvb_us

static int vp7045_read_eeprom(struct dvb_usb_device *d,u8 *buf, int len, int offset)
{
- int i = 0;
- u8 v,br[2];
+ int i, ret;
+ u8 v, br[2];
for (i=0; i < len; i++) {
v = offset + i;
- vp7045_usb_op(d,GET_EE_VALUE,&v,1,br,2,5);
+ ret = vp7045_usb_op(d, GET_EE_VALUE, &v, 1, br, 2, 5);
+ if (ret)
+ return ret;
+
buf[i] = br[1];
}
- deb_info("VP7045 EEPROM read (offs: %d, len: %d) : ",offset, i);
- debug_dump(buf,i,deb_info);
+ deb_info("VP7045 EEPROM read (offs: %d, len: %d) : ", offset, i);
+ debug_dump(buf, i, deb_info);
return 0;
}