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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 <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
steinar/wifi_calib_4_9_kernel
Sebastian Ott 2016-04-15 09:41:35 +02:00 committed by Martin Schwidefsky
parent 55f058e757
commit dba599091c
1 changed files with 10 additions and 6 deletions
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16
arch/s390/pci/pci_dma.c
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@ -457,7 +457,7 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
zdev->dma_table = dma_alloc_cpu_table(); zdev->dma_table = dma_alloc_cpu_table();
if (!zdev->dma_table) { if (!zdev->dma_table) {
rc = -ENOMEM; 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); zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
if (!zdev->iommu_bitmap) { if (!zdev->iommu_bitmap) {
rc = -ENOMEM; rc = -ENOMEM;
goto out_reg; goto free_dma_table;
} }
rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
(u64) zdev->dma_table); (u64) zdev->dma_table);
if (rc) if (rc)
goto out_reg; goto free_bitmap;
return 0;
out_reg: return 0;
free_bitmap:
vfree(zdev->iommu_bitmap);
zdev->iommu_bitmap = NULL;
free_dma_table:
dma_free_cpu_table(zdev->dma_table); dma_free_cpu_table(zdev->dma_table);
out_clean: zdev->dma_table = NULL;
out:
return rc; return rc;
} }