1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 7e4a9d1296bb..6e0cbe092220 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -340,6 +340,11 @@ static const struct vm_operations_struct mmap_mem_ops = {
 static int mmap_mem(struct file *file, struct vm_area_struct *vma)
 {
         size_t size = vma->vm_end - vma->vm_start;
+        phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
+
+        /* It's illegal to wrap around the end of the physical address space. */
+        if (offset + (phys_addr_t)size < offset)
+                return -EINVAL;
 
         if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
                 return -EINVAL;