On 2020-03-26 9:35 am, Jean-Philippe Brucker wrote:
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().
Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Fixes: edcd69ab9a32 ("iommu: Add virtio-iommu driver")
Reported-by: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
---
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 cce329d71fba..5eed75cd121f 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)
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