From patchwork Tue May 29 12:35:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cornelia Huck X-Patchwork-Id: 10435275 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8197D602BF for ; Tue, 29 May 2018 12:36:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7397B286C6 for ; Tue, 29 May 2018 12:36:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 685C3286E6; Tue, 29 May 2018 12:36:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1DCCC286C6 for ; Tue, 29 May 2018 12:36:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934070AbeE2MgI (ORCPT ); Tue, 29 May 2018 08:36:08 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47444 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933756AbeE2MfW (ORCPT ); Tue, 29 May 2018 08:35:22 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D46D981663D9; Tue, 29 May 2018 12:35:21 +0000 (UTC) Received: from localhost (dhcp-192-222.str.redhat.com [10.33.192.222]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8DE00111670D; Tue, 29 May 2018 12:35:21 +0000 (UTC) From: Cornelia Huck To: Martin Schwidefsky , Heiko Carstens Cc: Dong Jia Shi , Halil Pasic , linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Cornelia Huck Subject: [PULL 5/6] vfio: ccw: set ccw->cda to NULL defensively Date: Tue, 29 May 2018 14:35:11 +0200 Message-Id: <20180529123512.14393-6-cohuck@redhat.com> In-Reply-To: <20180529123512.14393-1-cohuck@redhat.com> References: <20180529123512.14393-1-cohuck@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 29 May 2018 12:35:21 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 29 May 2018 12:35:21 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'cohuck@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Message-Id: <20180523025645.8978-4-bjsdjshi@linux.ibm.com> Signed-off-by: Cornelia Huck --- 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 b0f20230fc72..dbe7c7ac9ac8 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -502,7 +502,7 @@ 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; @@ -522,18 +522,19 @@ 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; @@ -541,6 +542,12 @@ 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, @@ -570,7 +577,7 @@ 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); @@ -602,6 +609,8 @@ 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; }