From: Fenghua Yu Date: Tue, 17 Aug 2021 12:43:20 +0000 (+0800) Subject: iommu/vt-d: Fix PASID reference leak X-Git-Tag: accepted/tizen/unified/20230118.172025~6640^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=62ef907a045e1a81830941c48004d7af71c9d75a;p=platform%2Fkernel%2Flinux-rpi.git iommu/vt-d: Fix PASID reference leak A PASID reference is increased whenever a device is bound to an mm (and its PASID) successfully (i.e. the device's sdev user count is increased). But the reference is not dropped every time the device is unbound successfully from the mm (i.e. the device's sdev user count is decreased). The reference is dropped only once by calling intel_svm_free_pasid() when there isn't any device bound to the mm. intel_svm_free_pasid() drops the reference and only frees the PASID on zero reference. Fix the issue by dropping the PASID reference and freeing the PASID when no reference on successful unbinding the device by calling intel_svm_free_pasid() . Fixes: 4048377414162 ("iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers") Signed-off-by: Fenghua Yu Link: https://lore.kernel.org/r/20210813181345.1870742-1-fenghua.yu@intel.com Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210817124321.1517985-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 9b0f22b..4b9b3f3 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -675,7 +675,6 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree_rcu(sdev, rcu); if (list_empty(&svm->devs)) { - intel_svm_free_pasid(mm); if (svm->notifier.ops) { mmu_notifier_unregister(&svm->notifier, mm); /* Clear mm's pasid. */ @@ -690,6 +689,8 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) kfree(svm); } } + /* Drop a PASID reference and free it if no reference. */ + intel_svm_free_pasid(mm); } out: return ret;