From: Fenghua Yu Date: Sat, 28 Aug 2021 07:06:21 +0000 (+0800) Subject: iommu/vt-d: Fix PASID leak in intel_svm_unbind_mm() X-Git-Tag: v5.15~301^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a21518cb23a3c7d49bafcb59862fd389fd829d4b;p=platform%2Fkernel%2Flinux-starfive.git iommu/vt-d: Fix PASID leak in intel_svm_unbind_mm() 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 Co-developed-by: Jacob Pan Signed-off-by: Jacob Pan Signed-off-by: Fenghua Yu Link: https://lore.kernel.org/r/20210826215918.4073446-1-fenghua.yu@intel.com Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20210828070622.2437559-2-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 2014fe8..a3f84f2 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -514,9 +514,6 @@ 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);