Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1169613AbdDXMlG (ORCPT ); Mon, 24 Apr 2017 08:41:06 -0400 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:36233 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1169480AbdDXMk5 (ORCPT ); Mon, 24 Apr 2017 08:40:57 -0400 From: Jisheng Zhang To: CC: , , , , Jisheng Zhang Subject: [PATCH] usb: chipidea: udc: fix NULL pointer dereference if udc_start failed Date: Mon, 24 Apr 2017 20:35:51 +0800 Message-ID: <20170424123551.2465-1-jszhang@marvell.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-24_10:,, signatures=0 X-Proofpoint-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1704240225 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3187 Lines: 74 Fix below NULL pointer dereference. we set ci->roles[CI_ROLE_GADGET] too early in ci_hdrc_gadget_init(), if udc_start() fails due to some reason, the ci->roles[CI_ROLE_GADGET] check in ci_hdrc_gadget_destroy can't protect us. We fix this issue by only setting ci->roles[CI_ROLE_GADGET] if udc_start() succeed. [ 1.398550] Unable to handle kernel NULL pointer dereference at virtual address 00000000 ... [ 1.448600] PC is at dma_pool_free+0xb8/0xf0 [ 1.453012] LR is at dma_pool_free+0x28/0xf0 [ 2.113369] [] dma_pool_free+0xb8/0xf0 [ 2.118857] [] destroy_eps+0x4c/0x68 [ 2.124165] [] ci_hdrc_gadget_destroy+0x28/0x50 [ 2.130461] [] ci_hdrc_probe+0x588/0x7e8 [ 2.136129] [] platform_drv_probe+0x50/0xb8 [ 2.142066] [] driver_probe_device+0x1fc/0x2a8 [ 2.148270] [] __device_attach_driver+0x9c/0xf8 [ 2.154563] [] bus_for_each_drv+0x58/0x98 [ 2.160317] [] __device_attach+0xc4/0x138 [ 2.166072] [] device_initial_probe+0x10/0x18 [ 2.172185] [] bus_probe_device+0x94/0xa0 [ 2.177940] [] device_add+0x3f0/0x560 [ 2.183337] [] platform_device_add+0x180/0x240 [ 2.189541] [] ci_hdrc_add_device+0x440/0x4f8 [ 2.195654] [] ci_hdrc_usb2_probe+0x13c/0x2d8 [ 2.201769] [] platform_drv_probe+0x50/0xb8 [ 2.207705] [] driver_probe_device+0x1fc/0x2a8 [ 2.213910] [] __driver_attach+0xac/0xb0 [ 2.219575] [] bus_for_each_dev+0x60/0xa0 [ 2.225329] [] driver_attach+0x20/0x28 [ 2.230816] [] bus_add_driver+0x1d0/0x238 [ 2.236571] [] driver_register+0x60/0xf8 [ 2.242237] [] __platform_driver_register+0x44/0x50 [ 2.248891] [] ci_hdrc_usb2_driver_init+0x18/0x20 [ 2.255365] [] do_one_initcall+0x38/0x128 [ 2.261121] [] kernel_init_freeable+0x1ac/0x250 [ 2.267414] [] kernel_init+0x10/0x100 [ 2.272810] [] ret_from_fork+0x10/0x50 Signed-off-by: Jisheng Zhang --- drivers/usb/chipidea/udc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index f88e9157fad0..60a786c87c06 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -1984,6 +1984,7 @@ static void udc_id_switch_for_host(struct ci_hdrc *ci) int ci_hdrc_gadget_init(struct ci_hdrc *ci) { struct ci_role_driver *rdrv; + int ret; if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC)) return -ENXIO; @@ -1996,7 +1997,10 @@ int ci_hdrc_gadget_init(struct ci_hdrc *ci) rdrv->stop = udc_id_switch_for_host; rdrv->irq = udc_irq; rdrv->name = "gadget"; - ci->roles[CI_ROLE_GADGET] = rdrv; - return udc_start(ci); + ret = udc_start(ci); + if (!ret) + ci->roles[CI_ROLE_GADGET] = rdrv; + + return ret; } -- 2.11.0