math/mpmont.c (mpmont_reduce): Segfault if Karatsuba product is short.

[catacomb] / math / mpmont.c

diff --git a/math/mpmont.c b/math/mpmont.c
index 88efaca..1f9143b 100644 (file)
--- a/math/mpmont.c
+++ b/math/mpmont.c
@@ -160,6 +160,7 @@ mp *mpmont_reduce(mpmont *mm, mp *d, mp *a)
       u->vl = u->v + n;
     u = mp_mul(u, u, mm->m);
     d = mp_add(d, a, u);
+    MP_ENSURE(d, n);
     mp_drop(u);
   }