iommu/dma: Don't put uninitialised IOVA domains
authorRobin Murphy <robin.murphy@arm.com>
Tue, 9 Aug 2016 15:23:17 +0000 (16:23 +0100)
committerJoerg Roedel <jroedel@suse.de>
Tue, 9 Aug 2016 15:31:39 +0000 (17:31 +0200)
commit3ec60043f7c02e1f79e4a90045ff2d2e80042941
treeb6f7459538e1fcbe356b061ea65c4ec51b78f4c9
parent9a8a5dcf20eee254ce490f12d579ef80ee776eb6
iommu/dma: Don't put uninitialised IOVA domains

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>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
drivers/iommu/dma-iommu.c