From 4a8737ff068724f509d583fef404d349adba80d6 Mon Sep 17 00:00:00 2001
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Fri, 10 Dec 2021 10:03:09 +0100
Subject: [PATCH] can: gs_usb: fix use of uninitialized variable, detach device on reception of invalid USB data
Git-commit: 4a8737ff068724f509d583fef404d349adba80d6
Patch-mainline: v5.17-rc1
References: git-fixes
The received data contains the channel the received data is associated
with. If the channel number is bigger than the actual number of
channels assume broken or malicious USB device and shut it down.
This fixes the error found by clang:
| drivers/net/can/usb/gs_usb.c:386:6: error: variable 'dev' is used
| uninitialized whenever 'if' condition is true
| if (hf->channel >= GS_MAX_INTF)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
| drivers/net/can/usb/gs_usb.c:474:10: note: uninitialized use occurs here
| hf, dev->gs_hf_size, gs_usb_receive_bulk_callback,
| ^~~
Link: https://lore.kernel.org/all/20211210091158.408326-1-mkl@pengutronix.de
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/can/usb/gs_usb.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 1b400de00f51..d7ce2c5956f4 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -321,7 +321,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
/* device reports out of range channel id */
if (hf->channel >= GS_MAX_INTF)
- goto resubmit_urb;
+ goto device_detach;
dev = usbcan->canch[hf->channel];
@@ -406,6 +406,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
/* USB failure take down all interfaces */
if (rc == -ENODEV) {
+ device_detach:
for (rc = 0; rc < GS_MAX_INTF; rc++) {
if (usbcan->canch[rc])
netif_device_detach(usbcan->canch[rc]->netdev);
--
2.31.1