Add hardening for select()

This is unlikely to be used, since fd_set is
usually manipulated by macros, but it doesn't hurt
to add a simple comparison.

1 files changed, 12 insertions, 0 deletions

diff --git a/include/sys/select.h b/include/sys/select.h
index 29819be..f1cefee 100644
--- a/include/sys/select.h
+++ b/include/sys/select.h
@@ -67,6 +67,18 @@ _STI int __fortify_FD_ISSET(int __f, fd_set * _FORTIFY_POS0 __s)
 #undef FD_ISSET
 #define FD_ISSET(fd, set) __fortify_FD_ISSET(fd, set)
 
+#ifndef __clang__
+#undef select
+_FORTIFY_FN(select) int select(int nfds, fd_set* readfds,
+                  fd_set* writefds,
+                  fd_set* exceptfds,
+                  struct timeval *timeout){
+        if (nfds > FD_SETSIZE + 1)
+                __builtin_trap();
+        return __orig_select(nfds, readfds, writefds, exceptfds, timeout);
+}
+#endif
+
 #ifdef __cplusplus
 }
 #endif