From 9c01a49a7117fa824ee0703c9f46b2fa54dfd94d Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Thu, 26 Mar 2020 10:35:57 +0100 Subject: [PATCH] iommu/virtio: Fix freeing of incomplete domains [ 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 Signed-off-by: Jean-Philippe Brucker Reviewed-by: Robin Murphy Link: https://lore.kernel.org/r/20200326093558.2641019-3-jean-philippe@linaro.org Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- 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 3ea9d7682999..6c340a4f4fd2 100644 --- a/drivers/iommu/virtio-iommu.c +++ b/drivers/iommu/virtio-iommu.c @@ -614,18 +614,20 @@ 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)