[PATCH 3.16 72/72] can: peak_usb: fix slab info leak

Ben Hutchings
2019-12-08T13:55:57Z

From: Johan Hovold <johan@kernel.org>

commit f7a1337f0d29b98733c8824e165fca3371d7d4fd upstream.

Fix a small slab info leak due to a failure to clear the command buffer
at allocation.

The first 16 bytes of the command buffer are always sent to the device
in pcan_usb_send_cmd() even though only the first two may have been
initialised in case no argument payload is provided (e.g. when waiting
for a response).

Fixes: bb4785551f64 ("can: usb: PEAK-System Technik USB adapters driver core")
Reported-by: syzbot+863724e7128e14b26732@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/net/can/usb/peak_usb/pcan_usb_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -732,7 +732,7 @@ static int peak_usb_create_dev(struct pe
dev = netdev_priv(netdev);

/* allocate a buffer large enough to send commands */
- dev->cmd_buf = kmalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
+ dev->cmd_buf = kzalloc(PCAN_USB_MAX_CMD_LEN, GFP_KERNEL);
if (!dev->cmd_buf) {
err = -ENOMEM;
goto lbl_free_candev;