Subject: [PATCH v2] drivers: dma-mapping: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()

From: [email-masked] (Greg Kroah-Hartman)
Date: Thu, 25 May 2017 15:30:42 +0200

On Wed, May 03, 2017 at 03:57:48PM +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: Greg Kroah-Hartman <[email-masked]>
> Reported-by: Andrzej Hajda <[email-masked]>
> Acked-by: Laura Abbott <[email-masked]>
> Reviewed-by: Robin Murphy <[email-masked]>
> Signed-off-by: Catalin Marinas <[email-masked]>
> ---
> 
> Greg,
> 
> Please merge this patch via your tree (and therefore I haven't added
> your ack). Thanks.

I just tried to, but it doesn't apply to 4.12-rc2 :(

Can you refresh this and resend?

thanks,

greg k-h