From cab628d695ab19fb8665831780122f3798ed1830 Mon Sep 17 00:00:00 2001
From: Fenghua Yu <fenghua.yu@intel.com>
Date: Sat, 28 Aug 2021 15:06:21 +0800
Subject: [PATCH] iommu/vt-d: Fix PASID leak in intel_svm_unbind_mm()
Git-commit: a21518cb23a3c7d49bafcb59862fd389fd829d4b
Patch-mainline: v5.15-rc1
References: stable-5.14.8
[ 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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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);
--
2.26.2