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 5FF59C7EE25 for ; Mon, 12 Jun 2023 12:44:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234390AbjFLMoi (ORCPT ); Mon, 12 Jun 2023 08:44:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234600AbjFLMod (ORCPT ); Mon, 12 Jun 2023 08:44:33 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7DEEE47; Mon, 12 Jun 2023 05:44:30 -0700 (PDT) Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 35C9QvYD002272; Mon, 12 Jun 2023 12:44:20 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=AbqVcEBTgwpX78pdviKKVyjWrTI6YI8h2YEgR9e9Gvc=; b=kCo1pR4STXPu4x0rLsWVJBc3Uk+Uvkr1zmk5KMs5UMsnXaZnNJsYijd4gHk85or8ON+K S5z1nEQTpWyj7V+rVMagJSZjOeK9fgtli/iXXFwxNV4CkQvmBB7PTatY5awd9AG5iSA9 sA39PnxkQvGyYKP4MOgPFXW2b4cDnHzTsWVGJgYxg8RwVYZIMk2iTEJpemzFiklHXrfk W2dIAGxJKavcyBuTkTG1wQtcwOF+lXVTPNBCvixIUQlOeud92rDyg+RwsAZPOl0Uh7Ys g+Xe7OyT6Mx5MtEUzhvETmYc7snm9GlZKvDfftyarnQaP/ZptJmHgYoM+aXj7FSVT4y0 Sg== Received: from nalasppmta03.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3r4ggr3b27-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Jun 2023 12:44:19 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA03.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 35CCiHSp014000 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 12 Jun 2023 12:44:18 GMT Received: from [10.50.37.200] (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 15.2.986.42; Mon, 12 Jun 2023 05:44:14 -0700 Message-ID: <1d2aa1b5-56d1-b334-5f2d-2fe3fb42b0b1@quicinc.com> Date: Mon, 12 Jun 2023 18:14:11 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH] accel/qaic: Fix dereferencing freed memory To: Sukrut Bellary , Jeffrey Hugo , Oded Gabbay , Sumit Semwal , =?UTF-8?Q?Christian_K=c3=b6nig?= CC: , , , , , References: <20230610021200.377452-1-sukrut.bellary@linux.com> Content-Language: en-US From: Pranjal Ramajor Asha Kanojiya In-Reply-To: <20230610021200.377452-1-sukrut.bellary@linux.com> 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: uCWHrFY7FAqAC1J-jmAOGSzXxsWQAkpw X-Proofpoint-ORIG-GUID: uCWHrFY7FAqAC1J-jmAOGSzXxsWQAkpw X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-12_06,2023-06-09_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 mlxscore=0 mlxlogscore=999 malwarescore=0 phishscore=0 clxscore=1011 priorityscore=1501 spamscore=0 bulkscore=0 suspectscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306120110 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/10/2023 7:42 AM, Sukrut Bellary wrote: > smatch warning: > drivers/accel/qaic/qaic_data.c:620 qaic_free_object() error: > dereferencing freed memory 'obj->import_attach' > > obj->import_attach is detached and freed using dma_buf_detach(). > But used after free to decrease the dmabuf ref count using > dma_buf_put(). > > Fixes: ff13be830333 ("accel/qaic: Add datapath") > Signed-off-by: Sukrut Bellary > --- > drivers/accel/qaic/qaic_data.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/accel/qaic/qaic_data.c b/drivers/accel/qaic/qaic_data.c > index e42c1f9ffff8..7cba4d680ea8 100644 > --- a/drivers/accel/qaic/qaic_data.c > +++ b/drivers/accel/qaic/qaic_data.c > @@ -613,11 +613,13 @@ static int qaic_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struc > static void qaic_free_object(struct drm_gem_object *obj) > { > struct qaic_bo *bo = to_qaic_bo(obj); > + struct dma_buf *dmabuf; > > if (obj->import_attach) { > /* DMABUF/PRIME Path */ > + dmabuf = obj->import_attach->dmabuf; > dma_buf_detach(obj->import_attach->dmabuf, obj->import_attach); > - dma_buf_put(obj->import_attach->dmabuf); > + dma_buf_put(dmabuf); > } else { > /* Private buffer allocation path */ > qaic_free_sgt(bo->sgt); Reviewed-by: Pranjal Ramajor Asha Kanojiya