can: peak_usb: fix slab info leak

BugLink: https://bugs.launchpad.net/bugs/1853519
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")
Cc: stable <stable@vger.kernel.org>     # 3.4
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
index 059282a6065c6aff47d11c3a622e2f671910e340..85d92f129af2d8e1477e2ae385f40e66438ba938 100644 (file)
--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -776,7 +776,7 @@ static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
        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;