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path: root/drivers/iommu/intel-svm.c
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Diffstat (limited to 'drivers/iommu/intel-svm.c')
-rw-r--r--drivers/iommu/intel-svm.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index f620dccec8ee..f6697e55c2d4 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -24,6 +24,7 @@
#include <linux/pci-ats.h>
#include <linux/dmar.h>
#include <linux/interrupt.h>
+#include <asm/page.h>
static irqreturn_t prq_event_thread(int irq, void *d);
@@ -546,6 +547,14 @@ static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req)
return (requested & ~vma->vm_flags) != 0;
}
+static bool is_canonical_address(u64 addr)
+{
+ int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
+ long saddr = (long) addr;
+
+ return (((saddr << shift) >> shift) == saddr);
+}
+
static irqreturn_t prq_event_thread(int irq, void *d)
{
struct intel_iommu *iommu = d;
@@ -603,6 +612,11 @@ static irqreturn_t prq_event_thread(int irq, void *d)
/* If the mm is already defunct, don't handle faults. */
if (!mmget_not_zero(svm->mm))
goto bad_req;
+
+ /* If address is not canonical, return invalid response */
+ if (!is_canonical_address(address))
+ goto bad_req;
+
down_read(&svm->mm->mmap_sem);
vma = find_extend_vma(svm->mm, address);
if (!vma || address < vma->vm_start)