Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754240AbdDJQBJ (ORCPT ); Mon, 10 Apr 2017 12:01:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:37866 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754315AbdDJPeV (ORCPT ); Mon, 10 Apr 2017 11:34:21 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Sebastian Ott , Martin Schwidefsky , Sumit Semwal , Jiri Slaby Subject: [PATCH 3.12 050/142] s390/pci: fix use after free in dma_init Date: Mon, 10 Apr 2017 17:32:11 +0200 Message-Id: X-Mailer: git-send-email 2.12.2 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2094 Lines: 72 From: Sebastian Ott 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit dba599091c191d209b1499511a524ad9657c0e5a upstream. After a failure during registration of the dma_table (because of the function being in error state) we free its memory but don't reset the associated pointer to zero. When we then receive a notification from firmware (about the function being in error state) we'll try to walk and free the dma_table again. Fix this by resetting the dma_table pointer. In addition to that make sure that we free the iommu_bitmap when appropriate. Signed-off-by: Sebastian Ott Reviewed-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky Cc: Sumit Semwal Signed-off-by: Jiri Slaby --- arch/s390/pci/pci_dma.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index 7e5573acb063..9b76189d3375 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -416,7 +416,7 @@ int zpci_dma_init_device(struct zpci_dev *zdev) zdev->dma_table = dma_alloc_cpu_table(); if (!zdev->dma_table) { rc = -ENOMEM; - goto out_clean; + goto out; } zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET; @@ -424,7 +424,7 @@ int zpci_dma_init_device(struct zpci_dev *zdev) zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8); if (!zdev->iommu_bitmap) { rc = -ENOMEM; - goto out_reg; + goto free_dma_table; } rc = zpci_register_ioat(zdev, @@ -433,12 +433,16 @@ int zpci_dma_init_device(struct zpci_dev *zdev) zdev->start_dma + zdev->iommu_size - 1, (u64) zdev->dma_table); if (rc) - goto out_reg; - return 0; + goto free_bitmap; -out_reg: + return 0; +free_bitmap: + vfree(zdev->iommu_bitmap); + zdev->iommu_bitmap = NULL; +free_dma_table: dma_free_cpu_table(zdev->dma_table); -out_clean: + zdev->dma_table = NULL; +out: return rc; } -- 2.12.2