Re: [PATCH 1/2] iommu/dma: Don't put uninitialised IOVA domains

[Joerg Roedel <joro@8bytes.org>]

On Tue, Aug 09, 2016 at 04:23:17PM +0100, Robin Murphy wrote:
> Due to the limitations of having to wait until we see a device's DMA
> restrictions before we know how we want an IOVA domain initialised,
> there is a window for error if a DMA ops domain is allocated but later
> freed without ever being used. In that case, init_iova_domain() was
> never called, so calling put_iova_domain() from iommu_put_dma_cookie()
> ends up trying to take an uninitialised lock and crashing.
> 
> Make things robust by skipping the call unless the IOVA domain actually
> has been initialised, as we probably should have done from the start.
> 
> Fixes: 0db2e5d18f76 ("iommu: Implement common IOMMU ops for DMA mapping")
> Cc: stable@vger.kernel.org
> Reported-by: Nate Watterson <nwatters@codeaurora.org>
> Reviewed-by: Nate Watterson <nwatters@codeaurora.org>
> Tested-by: Nate Watterson <nwatters@codeaurora.org>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> Tested-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  drivers/iommu/dma-iommu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Wow, that was quick :)

Applied to iommu/fixes, thanks.