From dba599091c191d209b1499511a524ad9657c0e5a Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Fri, 15 Apr 2016 09:41:35 +0200 Subject: [PATCH] s390/pci: fix use after free in dma_init 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 --- 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 e595e89eac65..1ea8c07eab84 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -457,7 +457,7 @@ 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; } /* @@ -477,18 +477,22 @@ 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, 0, zdev->start_dma, zdev->end_dma, (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; }