vm audit: add VM_DONTEXPAND to mmap for drivers that need it

Drivers that register a ->fault handler, but do not range-check the
offset argument, must set VM_DONTEXPAND in the vm_flags in order to
prevent an expanding mremap from overflowing the resource.

I've audited the tree and attempted to fix these problems (usually by
adding VM_DONTEXPAND where it is not obvious).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/sound/usb/usx2y/usX2Yhwdep.c b/sound/usb/usx2y/usX2Yhwdep.c
index 6495534e..1558a5c 100644
--- a/sound/usb/usx2y/usX2Yhwdep.c
+++ b/sound/usb/usx2y/usX2Yhwdep.c
@@ -84,7 +84,7 @@
 		us428->us428ctls_sharedmem->CtlSnapShotLast = -2;
 	}
 	area->vm_ops = &us428ctls_vm_ops;
-	area->vm_flags |= VM_RESERVED;
+	area->vm_flags |= VM_RESERVED | VM_DONTEXPAND;
 	area->vm_private_data = hw->private_data;
 	return 0;
 }