1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c
index 286447a83dab..152552d2c306 100644
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -334,6 +334,7 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma,
         int rc = VM_FAULT_SIGBUS;
         phys_addr_t phys;
         pfn_t pfn;
+        unsigned int fault_size = PAGE_SIZE;
 
         if (check_vma(dax_dev, vma, __func__))
                 return VM_FAULT_SIGBUS;
@@ -344,6 +345,9 @@ static int __dax_dev_fault(struct dax_dev *dax_dev, struct vm_area_struct *vma,
                 return VM_FAULT_SIGBUS;
         }
 
+        if (fault_size != dax_region->align)
+                return VM_FAULT_SIGBUS;
+
         phys = pgoff_to_phys(dax_dev, vmf->pgoff, PAGE_SIZE);
         if (phys == -1) {
                 dev_dbg(dev, "%s: phys_to_pgoff(%#lx) failed\n", __func__,
@@ -389,6 +393,7 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev,
         phys_addr_t phys;
         pgoff_t pgoff;
         pfn_t pfn;
+        unsigned int fault_size = PMD_SIZE;
 
         if (check_vma(dax_dev, vma, __func__))
                 return VM_FAULT_SIGBUS;
@@ -405,6 +410,16 @@ static int __dax_dev_pmd_fault(struct dax_dev *dax_dev,
                 return VM_FAULT_SIGBUS;
         }
 
+        if (fault_size < dax_region->align)
+                return VM_FAULT_SIGBUS;
+        else if (fault_size > dax_region->align)
+                return VM_FAULT_FALLBACK;
+
+        /* if we are outside of the VMA */
+        if (pmd_addr < vma->vm_start ||
+                        (pmd_addr + PMD_SIZE) > vma->vm_end)
+                return VM_FAULT_SIGBUS;
+
         pgoff = linear_page_index(vma, pmd_addr);
         phys = pgoff_to_phys(dax_dev, pgoff, PMD_SIZE);
         if (phys == -1) {