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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot+863724e7128e14b26732@syzkaller.appspotmail.com,
        Johan Hovold <johan@kernel.org>,
        Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH 4.9 26/65] can: peak_usb: fix slab info leak
Date:   Mon, 11 Nov 2019 19:28:26 +0100
Message-Id: <20191111181345.895508122@linuxfoundation.org>
In-Reply-To: <20191111181331.917659011@linuxfoundation.org>
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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")
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>

---
 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
@@ -774,7 +774,7 @@ static int peak_usb_create_dev(const str
 	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;