[PATCH AUTOSEL 4.4 6/9] r8152: add missing endpoint sanity check

From: Sasha Levin
Date: Fri Jan 24 2020 - 09:22:46 EST


From: Johan Hovold <johan@xxxxxxxxxx>

[ Upstream commit 86f3f4cd53707ceeec079b83205c8d3c756eca93 ]

Add missing endpoint sanity check to probe in order to prevent a
NULL-pointer dereference (or slab out-of-bounds access) when retrieving
the interrupt-endpoint bInterval on ndo_open() in case a device lacks
the expected endpoints.

Fixes: 40a82917b1d3 ("net/usb/r8152: enable interrupt transfer")
Cc: hayeswang <hayeswang@xxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/usb/r8152.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 10dd307593e89..db8b489b0513c 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -4243,6 +4243,9 @@ static int rtl8152_probe(struct usb_interface *intf,
return -ENODEV;
}

+ if (intf->cur_altsetting->desc.bNumEndpoints < 3)
+ return -ENODEV;
+
usb_reset_device(udev);
netdev = alloc_etherdev(sizeof(struct r8152));
if (!netdev) {
--
2.20.1