From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Shuah Khan , Krzysztof Opasiak Subject: [PATCH 4.14 017/109] usbip: vudc: fix null pointer dereference on udc->lock Date: Fri, 16 Mar 2018 16:22:46 +0100 Message-Id: <20180316152330.899540834@linuxfoundation.org> In-Reply-To: <20180316152329.844663293@linuxfoundation.org> References: <20180316152329.844663293@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Colin Ian King commit df3334c223a033f562645712e832ca4cbb326bbf upstream. Currently the driver attempts to spin lock on udc->lock before a NULL pointer check is performed on udc, hence there is a potential null pointer dereference on udc->lock. Fix this by moving the null check on udc before the lock occurs. Fixes: ea6873a45a22 ("usbip: vudc: Add SysFS infrastructure for VUDC") Signed-off-by: Colin Ian King Acked-by: Shuah Khan Reviewed-by: Krzysztof Opasiak Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/usbip/vudc_sysfs.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/usb/usbip/vudc_sysfs.c +++ b/drivers/usb/usbip/vudc_sysfs.c @@ -117,10 +117,14 @@ static ssize_t store_sockfd(struct devic if (rv != 0) return -EINVAL; + if (!udc) { + dev_err(dev, "no device"); + return -ENODEV; + } spin_lock_irqsave(&udc->lock, flags); /* Don't export what we don't have */ - if (!udc || !udc->driver || !udc->pullup) { - dev_err(dev, "no device or gadget not bound"); + if (!udc->driver || !udc->pullup) { + dev_err(dev, "gadget not bound"); ret = -ENODEV; goto unlock; }