From patchwork Mon Aug 19 01:51:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 1148969 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=kvm-ppc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ozlabs.ru Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46BcNB3mphz9sND for ; Mon, 19 Aug 2019 11:51:22 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726132AbfHSBvV (ORCPT ); Sun, 18 Aug 2019 21:51:21 -0400 Received: from ozlabs.ru ([107.173.13.209]:58232 "EHLO ozlabs.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726103AbfHSBvV (ORCPT ); Sun, 18 Aug 2019 21:51:21 -0400 Received: from fstn1-p1.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id 0CA6BAE8001C; Sun, 18 Aug 2019 21:51:00 -0400 (EDT) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , David Gibson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, Jose Ricardo Ziviani , Alex Williamson Subject: [PATCH kernel] vfio/spapr_tce: Fix incorrect tce_iommu_group memory free Date: Mon, 19 Aug 2019 11:51:17 +1000 Message-Id: <20190819015117.94878-1-aik@ozlabs.ru> X-Mailer: git-send-email 2.17.1 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org The @tcegrp variable is used in 1) a loop over attached groups 2) it stores a pointer to a newly allocated tce_iommu_group if 1) found nothing. However the error handler does not distinguish how we got there and incorrectly releases memory for a found+incompatible group. This fixes it by adding another error handling case. Fixes: 0bd971676e68 ("powerpc/powernv/npu: Add compound IOMMU groups") Signed-off-by: Alexey Kardashevskiy Reviewed-by: Paul Mackerras --- The bug is there since 2157e7b82f3b but it would not appear in practice before 0bd971676e68, hence that "Fixes". Or it still should be 157e7b82f3b ("vfio: powerpc/spapr: Register memory and define IOMMU v2") ? Found it when tried adding a "compound PE" (GPU + NPUs) to a container with a passed through xHCI host. The compatibility test (->create_table should be equal) treats them as incompatible which might a bug (or we are just suboptimal here) on its own. --- drivers/vfio/vfio_iommu_spapr_tce.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 8ce9ad21129f..babef8b00daf 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -1234,7 +1234,7 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container, static int tce_iommu_attach_group(void *iommu_data, struct iommu_group *iommu_group) { - int ret; + int ret = 0; struct tce_container *container = iommu_data; struct iommu_table_group *table_group; struct tce_iommu_group *tcegrp = NULL; @@ -1287,13 +1287,13 @@ static int tce_iommu_attach_group(void *iommu_data, !table_group->ops->release_ownership) { if (container->v2) { ret = -EPERM; - goto unlock_exit; + goto free_exit; } ret = tce_iommu_take_ownership(container, table_group); } else { if (!container->v2) { ret = -EPERM; - goto unlock_exit; + goto free_exit; } ret = tce_iommu_take_ownership_ddw(container, table_group); if (!tce_groups_attached(container) && !container->tables[0]) @@ -1305,10 +1305,11 @@ static int tce_iommu_attach_group(void *iommu_data, list_add(&tcegrp->next, &container->group_list); } -unlock_exit: +free_exit: if (ret && tcegrp) kfree(tcegrp); +unlock_exit: mutex_unlock(&container->lock); return ret;