1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index c69e3f9ec958..50464833d0b8 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -484,6 +484,23 @@ struct page_req_dsc {
 };
 
 #define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x10)
+
+static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req)
+{
+        unsigned long requested = 0;
+
+        if (req->exe_req)
+                requested |= VM_EXEC;
+
+        if (req->rd_req)
+                requested |= VM_READ;
+
+        if (req->wr_req)
+                requested |= VM_WRITE;
+
+        return (requested & ~vma->vm_flags) != 0;
+}
+
 static irqreturn_t prq_event_thread(int irq, void *d)
 {
         struct intel_iommu *iommu = d;
@@ -539,6 +556,9 @@ static irqreturn_t prq_event_thread(int irq, void *d)
                 if (!vma || address < vma->vm_start)
                         goto invalid;
 
+                if (access_error(vma, req))
+                        goto invalid;
+
                 ret = handle_mm_fault(svm->mm, vma, address,
                                       req->wr_req ? FAULT_FLAG_WRITE : 0);
                 if (ret & VM_FAULT_ERROR)