Index: lib/sanitizer_common/sanitizer_common_interceptors.inc
===================================================================
--- lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -2448,7 +2448,7 @@
 INTERCEPTOR(uptr, ptrace, int request, int pid, void *addr, void *data) {
   void *ctx;
   COMMON_INTERCEPTOR_ENTER(ctx, ptrace, request, pid, addr, data);
-  __sanitizer_iovec local_iovec;
+  __sanitizer_iovec local_iovec = {0, 0};
 
   if (data) {
     if (request == ptrace_setregs)
Index: lib/sanitizer_common/sanitizer_posix.cc
===================================================================
--- lib/sanitizer_common/sanitizer_posix.cc
+++ lib/sanitizer_common/sanitizer_posix.cc
@@ -177,6 +177,7 @@
     case RdOnly: flags = O_RDONLY; break;
     case WrOnly: flags = O_WRONLY | O_CREAT; break;
     case RdWr: flags = O_RDWR | O_CREAT; break;
+    default: flags = O_RDONLY; break;
   }
   fd_t res = internal_open(filename, flags, 0660);
   if (internal_iserror(res, errno_p))