[PATCH 4.19 104/323] media: usb: dvd-usb: fix uninit-value bug in dibusb_read_eeprom_byte()

From: Greg Kroah-Hartman
Date: Wed Nov 24 2021 - 07:58:14 EST


From: Anant Thazhemadam <anant.thazhemadam@xxxxxxxxx>

[ Upstream commit 899a61a3305d49e8a712e9ab20d0db94bde5929f ]

In dibusb_read_eeprom_byte(), if dibusb_i2c_msg() fails, val gets
assigned an value that's not properly initialized.
Using kzalloc() in place of kmalloc() for the buffer fixes this issue,
as the val can now be set to 0 in the event dibusb_i2c_msg() fails.

Reported-by: syzbot+e27b4fd589762b0b9329@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: syzbot+e27b4fd589762b0b9329@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@xxxxxxxxx>
Signed-off-by: Sean Young <sean@xxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/usb/dvb-usb/dibusb-common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/usb/dvb-usb/dibusb-common.c b/drivers/media/usb/dvb-usb/dibusb-common.c
index fb1b4f2d5f9de..85b7838b3ede3 100644
--- a/drivers/media/usb/dvb-usb/dibusb-common.c
+++ b/drivers/media/usb/dvb-usb/dibusb-common.c
@@ -226,7 +226,7 @@ int dibusb_read_eeprom_byte(struct dvb_usb_device *d, u8 offs, u8 *val)
u8 *buf;
int rc;

- buf = kmalloc(2, GFP_KERNEL);
+ buf = kzalloc(2, GFP_KERNEL);
if (!buf)
return -ENOMEM;

--
2.33.0