Re: [PATCH] drivers: dma-mapping: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()

[Catalin Marinas]

On Tue, Apr 25, 2017 at 07:22:23PM +0100, Catalin Marinas wrote:
> The dma_common_pages_remap() function allocates a vm_struct object and
> initialises the pages pointer to value passed as argument. However, when
> this function is called dma_common_contiguous_remap(), the pages array
> is only temporarily allocated, being freed shortly after
> dma_common_contiguous_remap() returns. Architecture code checking the
> validity of an area->pages pointer would incorrectly dereference already
> freed pointers. This has been exposed by the arm64 commit 44176bb38fa4
> ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").
> 
> Fixes: 513510ddba96 ("common: dma-mapping: introduce common remapping functions")
> Cc: Laura Abbott <labbott@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Reported-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>

Small correction on the subject, the prefix should be something like:

drivers: dma-mapping:

It's not an arm64 patch.

-- 
Catalin