[PATCH 3.16 011/134] zd1211rw: fix NULL-deref at probe

Ben Hutchings
2017-08-18T13:15:41Z

From: Johan Hovold <johan@kernel.org>

commit ca260ece6a57dc7d751e0685f51fa2c55d851873 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer or accessing memory beyond the endpoint array should a
malicious device lack the expected endpoints.

Fixes: a1030e92c150 ("[PATCH] zd1211rw: Convert installer CDROM device into WLAN device")
Cc: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/wireless/zd1211rw/zd_usb.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -1278,6 +1278,9 @@ static int eject_installer(struct usb_in
u8 bulk_out_ep;
int r;

+ if (iface_desc->desc.bNumEndpoints < 2)
+ return -ENODEV;
+
/* Find bulk out endpoint */
for (r = 1; r >= 0; r--) {
endpoint = &iface_desc->endpoint[r].desc;