[PATCH 5.13 107/300] media: dvb-usb: fix uninit-value in dvb_usb_adapter_dvb_init

Greg Kroah-Hartman
2021-09-13T14:01:19Z

From: Dongliang Mu <mudongliangabcd@gmail.com>

[ Upstream commit c5453769f77ce19a5b03f1f49946fd3f8a374009 ]

If dibusb_read_eeprom_byte fails, the mac address is not initialized.
And nova_t_read_mac_address does not handle this failure, which leads to
the uninit-value in dvb_usb_adapter_dvb_init.

Fix this by handling the failure of dibusb_read_eeprom_byte.

Reported-by: syzbot+e27b4fd589762b0b9329@syzkaller.appspotmail.com
Fixes: 786baecfe78f ("[media] dvb-usb: move it to drivers/media/usb/dvb-usb")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/dvb-usb/nova-t-usb2.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/nova-t-usb2.c b/drivers/media/usb/dvb-usb/nova-t-usb2.c
index e7b290552b66..9c0eb0d40822 100644
--- a/drivers/media/usb/dvb-usb/nova-t-usb2.c
+++ b/drivers/media/usb/dvb-usb/nova-t-usb2.c
@@ -130,7 +130,7 @@ ret:

static int nova_t_read_mac_address (struct dvb_usb_device *d, u8 mac[6])
{
- int i;
+ int i, ret;
u8 b;

mac[0] = 0x00;
@@ -139,7 +139,9 @@ static int nova_t_read_mac_address (struct dvb_usb_device *d, u8 mac[6])

/* this is a complete guess, but works for my box */
for (i = 136; i < 139; i++) {
- dibusb_read_eeprom_byte(d,i, &b);
+ ret = dibusb_read_eeprom_byte(d, i, &b);
+ if (ret)
+ return ret;

mac[5 - (i - 136)] = b;
}
--
2.30.2