From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753952AbeEWCp2 (ORCPT ); Tue, 22 May 2018 22:45:28 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33872 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753916AbeEWCpW (ORCPT ); Tue, 22 May 2018 22:45:22 -0400 From: Dong Jia Shi To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org Cc: cohuck@redhat.com, borntraeger@de.ibm.com, bjsdjshi@linux.ibm.com, pasic@linux.ibm.com, pmorel@linux.ibm.com, Dong Jia Shi Subject: [PATCH v3 3/4] vfio: ccw: set ccw->cda to NULL defensively Date: Wed, 23 May 2018 04:45:01 +0200 X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180523024502.94244-1-bjsdjshi@linux.ibm.com> References: <20180523024502.94244-1-bjsdjshi@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18052302-0016-0000-0000-000008C8362B X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009069; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000261; SDB=6.01036288; UDB=6.00530120; IPR=6.00815416; MB=3.00021249; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-23 02:45:19 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052302-0017-0000-0000-00003EDB8B77 Message-Id: <20180523024502.94244-4-bjsdjshi@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-23_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805230023 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dong Jia Shi Let's avoid free on ccw->cda that points to a guest address or an already freed memory area by setting it to NULL if memory allocation didn't happen or failed. Signed-off-by: Dong Jia Shi --- drivers/s390/cio/vfio_ccw_cp.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 262f969b3b33..63c3df1c2ff2 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -491,7 +491,7 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, struct ccw1 *ccw; struct pfn_array_table *pat; unsigned long *idaws; - int idaw_nr; + int ret; ccw = chain->ch_ccw + idx; @@ -511,18 +511,19 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, * needed when translating a direct ccw to a idal ccw. */ pat = chain->ch_pat + idx; - if (pfn_array_table_init(pat, 1)) - return -ENOMEM; - idaw_nr = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, - ccw->cda, ccw->count); - if (idaw_nr < 0) - return idaw_nr; + ret = pfn_array_table_init(pat, 1); + if (ret) + goto out_init; + + ret = pfn_array_alloc_pin(pat->pat_pa, cp->mdev, ccw->cda, ccw->count); + if (ret < 0) + goto out_init; /* Translate this direct ccw to a idal ccw. */ - idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL); + idaws = kcalloc(ret, sizeof(*idaws), GFP_DMA | GFP_KERNEL); if (!idaws) { - pfn_array_table_unpin_free(pat, cp->mdev); - return -ENOMEM; + ret = -ENOMEM; + goto out_unpin; } ccw->cda = (__u32) virt_to_phys(idaws); ccw->flags |= CCW_FLAG_IDA; @@ -530,6 +531,12 @@ static int ccwchain_fetch_direct(struct ccwchain *chain, pfn_array_table_idal_create_words(pat, idaws); return 0; + +out_unpin: + pfn_array_table_unpin_free(pat, cp->mdev); +out_init: + ccw->cda = 0; + return ret; } static int ccwchain_fetch_idal(struct ccwchain *chain, @@ -559,7 +566,7 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, pat = chain->ch_pat + idx; ret = pfn_array_table_init(pat, idaw_nr); if (ret) - return ret; + goto out_init; /* Translate idal ccw to use new allocated idaws. */ idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL); @@ -591,6 +598,8 @@ static int ccwchain_fetch_idal(struct ccwchain *chain, kfree(idaws); out_unpin: pfn_array_table_unpin_free(pat, cp->mdev); +out_init: + ccw->cda = 0; return ret; } -- 2.16.3