From: Jean-Philippe Brucker <jean-phili...@linaro.org> [ Upstream commit 7062af3ed2ba451029e3733d9f677c68f5ea9e77 ]
Calling viommu_domain_free() on a domain that hasn't been finalised (not attached to any device, for example) can currently cause an Oops, because we attempt to call ida_free() on ID 0, which may either be unallocated or used by another domain. Only initialise the vdomain->viommu pointer, which denotes a finalised domain, at the end of a successful viommu_domain_finalise(). Fixes: edcd69ab9a32 ("iommu: Add virtio-iommu driver") Reported-by: Eric Auger <eric.au...@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org> Reviewed-by: Robin Murphy <robin.mur...@arm.com> Link: https://lore.kernel.org/r/20200326093558.2641019-3-jean-phili...@linaro.org Signed-off-by: Joerg Roedel <jroe...@suse.de> Signed-off-by: Sasha Levin <sas...@kernel.org> --- drivers/iommu/virtio-iommu.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 315c7cc4f99d8..779a6025b5962 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -613,18 +613,20 @@ static int viommu_domain_finalise(struct viommu_dev *viommu, int ret; struct viommu_domain *vdomain = to_viommu_domain(domain); - vdomain->viommu = viommu; - vdomain->map_flags = viommu->map_flags; + ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, + viommu->last_domain, GFP_KERNEL); + if (ret < 0) + return ret; + + vdomain->id = (unsigned int)ret; domain->pgsize_bitmap = viommu->pgsize_bitmap; domain->geometry = viommu->geometry; - ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, - viommu->last_domain, GFP_KERNEL); - if (ret >= 0) - vdomain->id = (unsigned int)ret; + vdomain->map_flags = viommu->map_flags; + vdomain->viommu = viommu; - return ret > 0 ? 0 : ret; + return 0; } static void viommu_domain_free(struct iommu_domain *domain) -- 2.20.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu