[PATCH AUTOSEL 4.19 031/177] media: flexcop-usb: fix NULL-ptr deref in flexcop_usb_transfer_init()

Sasha Levin
2019-12-10T21:33:05Z

From: Yang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 649cd16c438f51d4cd777e71ca1f47f6e0c5e65d ]

If usb_set_interface() failed, iface->cur_altsetting will
not be assigned and it will be used in flexcop_usb_transfer_init()
It may lead a NULL pointer dereference.

Check usb_set_interface() return value in flexcop_usb_init()
and return failed to avoid using this NULL pointer.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/b2c2/flexcop-usb.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/b2c2/flexcop-usb.c b/drivers/media/usb/b2c2/flexcop-usb.c
index ac4fddfd0a43f..f1807c16438dd 100644
--- a/drivers/media/usb/b2c2/flexcop-usb.c
+++ b/drivers/media/usb/b2c2/flexcop-usb.c
@@ -503,7 +503,13 @@ static int flexcop_usb_transfer_init(struct flexcop_usb *fc_usb)
static int flexcop_usb_init(struct flexcop_usb *fc_usb)
{
/* use the alternate setting with the larges buffer */
- usb_set_interface(fc_usb->udev,0,1);
+ int ret = usb_set_interface(fc_usb->udev, 0, 1);
+
+ if (ret) {
+ err("set interface failed.");
+ return ret;
+ }
+
switch (fc_usb->udev->speed) {
case USB_SPEED_LOW:
err("cannot handle USB speed because it is too slow.");
--
2.20.1