| From 0fa53b848dc0bd654cab971a29f76dcaaf408903 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sat, 28 Aug 2021 15:06:21 +0800 |
| Subject: iommu/vt-d: Fix PASID leak in intel_svm_unbind_mm() |
| |
| From: Fenghua Yu <fenghua.yu@intel.com> |
| |
| [ Upstream commit a21518cb23a3c7d49bafcb59862fd389fd829d4b ] |
| |
| The mm->pasid will be used in intel_svm_free_pasid() after load_pasid() |
| during unbinding mm. Clearing it in load_pasid() will cause PASID cannot |
| be freed in intel_svm_free_pasid(). |
| |
| Additionally mm->pasid was updated already before load_pasid() during pasid |
| allocation. No need to update it again in load_pasid() during binding mm. |
| Don't update mm->pasid to avoid the issues in both binding mm and unbinding |
| mm. |
| |
| Fixes: 4048377414162 ("iommu/vt-d: Use iommu_sva_alloc(free)_pasid() helpers") |
| Reported-and-tested-by: Dave Jiang <dave.jiang@intel.com> |
| Co-developed-by: Jacob Pan <jacob.jun.pan@linux.intel.com> |
| Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> |
| Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> |
| Link: https://lore.kernel.org/r/20210826215918.4073446-1-fenghua.yu@intel.com |
| Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> |
| Link: https://lore.kernel.org/r/20210828070622.2437559-2-baolu.lu@linux.intel.com |
| Signed-off-by: Joerg Roedel <jroedel@suse.de> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/iommu/intel/svm.c | 3 --- |
| 1 file changed, 3 deletions(-) |
| |
| diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c |
| index 4b9b3f35ba0e..ceeca633a5f9 100644 |
| --- a/drivers/iommu/intel/svm.c |
| +++ b/drivers/iommu/intel/svm.c |
| @@ -516,9 +516,6 @@ static void load_pasid(struct mm_struct *mm, u32 pasid) |
| { |
| mutex_lock(&mm->context.lock); |
| |
| - /* Synchronize with READ_ONCE in update_pasid(). */ |
| - smp_store_release(&mm->pasid, pasid); |
| - |
| /* Update PASID MSR on all CPUs running the mm's tasks. */ |
| on_each_cpu_mask(mm_cpumask(mm), _load_pasid, NULL, true); |
| |
| -- |
| 2.33.0 |
| |
