IB/hfi: Protect against writable mmap

The device/port status is not intended to be changed from user space. Prevent a user from mapping them as write or execute. Reviewed-by: Dennis Dalessandro <[email protected]> Signed-off-by: Ira Weiny <[email protected]> Signed-off-by: Dennis Dalessandro <[email protected]> Signed-off-by: Doug Ledford <[email protected]>
adn770 · Apr 28, 2017 · 1222026 · 1222026
1 parent ee495ad
commit 1222026
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -597,6 +597,10 @@ static int hfi1_file_mmap(struct file *fp, struct vm_area_struct *vma)
 		vmf = 1;
 		break;
 	case STATUS:
+		if (flags & (unsigned long)(VM_WRITE | VM_EXEC)) {
+			ret = -EPERM;
+			goto done;
+		}
 		memaddr = kvirt_to_phys((void *)dd->status);
 		memlen = PAGE_SIZE;
 		flags |= VM_IO | VM_DONTEXPAND;