diff -r 28f71af02b69 Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c	Wed Nov 13 14:17:30 2013 +0100
+++ b/Objects/bytearrayobject.c	Wed Nov 13 22:14:17 2013 +0100
@@ -482,8 +482,20 @@ bytearray_setslice_linear(PyByteArrayObj
         }
         /* XXX(nnorwitz): need to verify this can't overflow! */
         if (PyByteArray_Resize(
-                (PyObject *)self, Py_SIZE(self) + growth) < 0)
+                (PyObject *)self, Py_SIZE(self) + growth) < 0) {
+            if (growth < 0) {
+                if (lo == 0) {
+                    self->ob_start += growth;
+                }
+                else {
+                    /* memmove() removed bytes, the bytearray object cannot be
+                       restored in its previous state. Update the size to make
+                       at least the object consistent. */
+                    Py_SIZE(self) += growth;
+                }
+            }
             return -1;
+        }
         buf = PyByteArray_AS_STRING(self);
         if (growth > 0) {
             /* Make the place for the additional bytes */