Avoid potential overflow in range check. #273431.

(Alexandre Duret-Lutz, adl@gnu.org)

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12173

diff --git a/coregrind/m_debuginfo/debuginfo.c b/coregrind/m_debuginfo/debuginfo.c
index 106866a86fd7a7fa51415fa8f167169f4cb8d939..284d6679965f60ca281671efe60560a7c857505a 100644 (file)
--- a/coregrind/m_debuginfo/debuginfo.c
+++ b/coregrind/m_debuginfo/debuginfo.c
@@ -2036,7 +2036,7 @@ UWord evalCfiExpr ( XArray* exprs, Int ix,
          a = evalCfiExpr( exprs, e->Cex.Deref.ixAddr, eec, ok );
          if (!(*ok)) return 0;
          if (a < eec->min_accessible
-             || (a + sizeof(UWord) - 1) > eec->max_accessible) {
+             || a > eec->max_accessible - sizeof(UWord) + 1) {
             *ok = False;
             return 0;
          }