From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35218 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752722AbeBBRBo (ORCPT ); Fri, 2 Feb 2018 12:01:44 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Felipe Balbi , Sasha Levin Subject: [PATCH 4.4 53/67] usb: gadget: dont dereference g until after it has been null checked Date: Fri, 2 Feb 2018 17:58:22 +0100 Message-Id: <20180202140821.185771025@linuxfoundation.org> In-Reply-To: <20180202140815.091718203@linuxfoundation.org> References: <20180202140815.091718203@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Colin Ian King [ Upstream commit b2fc059fa549fe6881d4c1f8d698b0f50bcd16ec ] Avoid dereferencing pointer g until after g has been sanity null checked; move the assignment of cdev much later when it is required into a more local scope. Detected by CoverityScan, CID#1222135 ("Dereference before null check") Fixes: b785ea7ce662 ("usb: gadget: composite: fix ep->maxburst initialization") Signed-off-by: Colin Ian King Signed-off-by: Felipe Balbi Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/composite.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -104,7 +104,6 @@ int config_ep_by_speed(struct usb_gadget struct usb_function *f, struct usb_ep *_ep) { - struct usb_composite_dev *cdev = get_gadget_data(g); struct usb_endpoint_descriptor *chosen_desc = NULL; struct usb_descriptor_header **speed_desc = NULL; @@ -176,8 +175,12 @@ ep_found: _ep->maxburst = comp_desc->bMaxBurst + 1; break; default: - if (comp_desc->bMaxBurst != 0) + if (comp_desc->bMaxBurst != 0) { + struct usb_composite_dev *cdev; + + cdev = get_gadget_data(g); ERROR(cdev, "ep0 bMaxBurst must be 0\n"); + } _ep->maxburst = 1; break; }