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* [PATCH] iommu/dma: Fix leak in non-contiguous API
@ 2021-07-23  1:05 Ezequiel Garcia
  2021-07-23  5:09 ` Christoph Hellwig
  2021-07-26 12:27 ` Joerg Roedel
  0 siblings, 2 replies; 3+ messages in thread
From: Ezequiel Garcia @ 2021-07-23  1:05 UTC (permalink / raw)
  To: iommu, linux-media
  Cc: Will Deacon, stable, Ricardo Ribalda, kernel, Ezequiel Garcia,
	Christoph Hellwig

Currently, iommu_dma_alloc_noncontiguous() allocates a
struct dma_sgt_handle object to hold some state needed for
iommu_dma_free_noncontiguous().

However, the handle is neither freed nor returned explicitly by
the ->alloc_noncontiguous method, and therefore seems leaked.
This was found by code inspection, so please review carefully and test.

As a side note, it appears the struct dma_sgt_handle type is exposed
to users of the DMA-API by linux/dma-map-ops.h, but is has no users
or functions returning the type explicitly.

This may indicate it's a good idea to move the struct dma_sgt_handle type
to drivers/iommu/dma-iommu.c. The decision is left to maintainers :-)

Cc: stable@vger.kernel.org
Fixes: e817ee5f2f95c ("dma-iommu: implement ->alloc_noncontiguous")
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
 drivers/iommu/dma-iommu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4e34e8b26579..16c06a1aab80 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -768,6 +768,7 @@ static void iommu_dma_free_noncontiguous(struct device *dev, size_t size,
 	__iommu_dma_unmap(dev, sgt->sgl->dma_address, size);
 	__iommu_dma_free_pages(sh->pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
 	sg_free_table(&sh->sgt);
+	kfree(sh);
 }
 #endif /* CONFIG_DMA_REMAP */
 
-- 
2.32.0

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^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] iommu/dma: Fix leak in non-contiguous API
  2021-07-23  1:05 [PATCH] iommu/dma: Fix leak in non-contiguous API Ezequiel Garcia
@ 2021-07-23  5:09 ` Christoph Hellwig
  2021-07-26 12:27 ` Joerg Roedel
  1 sibling, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2021-07-23  5:09 UTC (permalink / raw)
  To: Ezequiel Garcia
  Cc: stable, iommu, Ricardo Ribalda, kernel, Will Deacon,
	Christoph Hellwig, linux-media

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

> As a side note, it appears the struct dma_sgt_handle type is exposed
> to users of the DMA-API by linux/dma-map-ops.h, but is has no users
> or functions returning the type explicitly.
> 
> This may indicate it's a good idea to move the struct dma_sgt_handle type
> to drivers/iommu/dma-iommu.c. The decision is left to maintainers :-)

linux/dma-map-ops.h is a helper header for the dma_ops implementations,
not for users of the DMA API.  sgt_handle, which references
dma_sgt_handle is used in kernel/dma/mapping.c
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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] iommu/dma: Fix leak in non-contiguous API
  2021-07-23  1:05 [PATCH] iommu/dma: Fix leak in non-contiguous API Ezequiel Garcia
  2021-07-23  5:09 ` Christoph Hellwig
@ 2021-07-26 12:27 ` Joerg Roedel
  1 sibling, 0 replies; 3+ messages in thread
From: Joerg Roedel @ 2021-07-26 12:27 UTC (permalink / raw)
  To: Ezequiel Garcia
  Cc: stable, iommu, Ricardo Ribalda, kernel, Will Deacon,
	Christoph Hellwig, linux-media

On Thu, Jul 22, 2021 at 10:05:52PM -0300, Ezequiel Garcia wrote:
>  drivers/iommu/dma-iommu.c | 1 +
>  1 file changed, 1 insertion(+)

Applied to iommu/fixes, thanks.
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^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-07-26 12:27 UTC | newest]

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2021-07-23  1:05 [PATCH] iommu/dma: Fix leak in non-contiguous API Ezequiel Garcia
2021-07-23  5:09 ` Christoph Hellwig
2021-07-26 12:27 ` Joerg Roedel

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