From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A400ECAAD8 for ; Thu, 22 Sep 2022 19:50:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232388AbiIVTuC (ORCPT ); Thu, 22 Sep 2022 15:50:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232490AbiIVTtz (ORCPT ); Thu, 22 Sep 2022 15:49:55 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA4B92C11B; Thu, 22 Sep 2022 12:49:51 -0700 (PDT) Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28MJk0oL027564; 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Thu, 22 Sep 2022 19:48:59 GMT Received: from [10.110.101.161] (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.29; Thu, 22 Sep 2022 12:48:58 -0700 Message-ID: <668ebc3a-b731-cd0c-0f60-ba9faabbf978@quicinc.com> Date: Thu, 22 Sep 2022 12:48:49 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [Freedreno] [PATCH v2 01/10] drm/msm: fix use-after-free on probe deferral To: Johan Hovold , Douglas Anderson , Dmitry Baryshkov , "Rob Clark" , Abhinav Kumar CC: , Neil Armstrong , Daniel Vetter , Jonas Karlman , , Bjorn Andersson , , , Jernej Skrabec , Stephen Boyd , Robert Foss , Andrzej Hajda , Manivannan Sadhasivam , , Sean Paul , Steev Klimaszewski , Laurent Pinchart References: <20220913085320.8577-1-johan+linaro@kernel.org> <20220913085320.8577-2-johan+linaro@kernel.org> Content-Language: en-US From: Kuogee Hsieh In-Reply-To: <20220913085320.8577-2-johan+linaro@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: XFS2v7F2z7Z4grplLaqVY6tfI2QTR_EF X-Proofpoint-ORIG-GUID: XFS2v7F2z7Z4grplLaqVY6tfI2QTR_EF X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-22_14,2022-09-22_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=0 suspectscore=0 phishscore=0 spamscore=0 mlxlogscore=999 clxscore=1011 lowpriorityscore=0 adultscore=0 malwarescore=0 mlxscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2209220128 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/13/2022 1:53 AM, Johan Hovold wrote: > The bridge counter was never reset when tearing down the DRM device so > that stale pointers to deallocated structures would be accessed on the > next tear down (e.g. after a second late bind deferral). > > Given enough bridges and a few probe deferrals this could currently also > lead to data beyond the bridge array being corrupted. > > Fixes: d28ea556267c ("drm/msm: properly add and remove internal bridges") > Fixes: a3376e3ec81c ("drm/msm: convert to drm_bridge") > Cc: stable@vger.kernel.org # 3.12 > Reviewed-by: Dmitry Baryshkov > Signed-off-by: Johan Hovold Tested-by: Kuogee Hsieh Reviewed-by: Kuogee Hsieh > --- > drivers/gpu/drm/msm/msm_drv.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c > index 391d86b54ded..d254fe2507ec 100644 > --- a/drivers/gpu/drm/msm/msm_drv.c > +++ b/drivers/gpu/drm/msm/msm_drv.c > @@ -241,6 +241,7 @@ static int msm_drm_uninit(struct device *dev) > > for (i = 0; i < priv->num_bridges; i++) > drm_bridge_remove(priv->bridges[i]); > + priv->num_bridges = 0; > > pm_runtime_get_sync(dev); > msm_irq_uninstall(ddev);