Set FD_CLOEXEC on opened files before exec from lua script is called

Lubos Kardos · Lubos Kardos · commit 7a7c31f551ff · 2016-05-31T10:27:01.000+02:00
rhbz:919801
diff --git a/luaext/lposix.c b/luaext/lposix.c
@@ -335,10 +335,22 @@ static int Pexec(lua_State *L)			/** exec(path,[args]) */
 	const char *path = luaL_checkstring(L, 1);
 	int i,n=lua_gettop(L);
 	char **argv;
+	int flag, fdno, open_max;
 
 	if (!have_forked)
 	    return luaL_error(L, "exec not permitted in this context");
 
+	open_max = sysconf(_SC_OPEN_MAX);
+	if (open_max == -1) {
+	    open_max = 1024;
+	}
+	for (fdno = 3; fdno < open_max; fdno++) {
+	    flag = fcntl(fdno, F_GETFD);
+	    if (flag == -1 || (flag & FD_CLOEXEC))
+		continue;
+	    fcntl(fdno, F_SETFD, FD_CLOEXEC);
+	}
+
 	argv = malloc((n+1)*sizeof(char*));
 	if (argv==NULL) return luaL_error(L,"not enough memory");
 	argv[0] = (char*)path;
