Procházet zdrojové kódy

Improve execsh() and don't allow anonymous shells

This patch improves the shell selection on execsh and forbid
shell with users don't registered in the passwd file.
Roberto E. Vargas Caballero před 10 roky
rodič
revize
a3549c2eec
1 změnil soubory, kde provedl 17 přidání a 13 odebrání
  1. 17 13
      st.c

+ 17 - 13
st.c

@@ -1139,23 +1139,29 @@ die(const char *errstr, ...) {
 
 void
 execsh(void) {
-	char **args;
-	char *envshell = getenv("SHELL");
-	const struct passwd *pass = getpwuid(getuid());
+	char **args, *sh;
+	const struct passwd *pw;
 	char buf[sizeof(long) * 8 + 1];
 
+	errno = 0;
+	if((pw = getpwuid(getuid())) == NULL) {
+		if(errno)
+			die("getpwuid:%s\n", strerror(errno));
+		else
+			die("who are you?\n");
+	}
 	unsetenv("COLUMNS");
 	unsetenv("LINES");
 	unsetenv("TERMCAP");
 
-	if(pass) {
-		setenv("LOGNAME", pass->pw_name, 1);
-		setenv("USER", pass->pw_name, 1);
-		setenv("SHELL", pass->pw_shell, 0);
-		setenv("HOME", pass->pw_dir, 0);
-	}
-
+	sh = (pw->pw_shell[0]) ? pw->pw_shell : shell;
 	snprintf(buf, sizeof(buf), "%lu", xw.win);
+
+	setenv("LOGNAME", pw->pw_name, 1);
+	setenv("USER", pw->pw_name, 1);
+	setenv("SHELL", sh, 1);
+	setenv("HOME", pw->pw_dir, 1);
+	setenv("TERM", termname, 1);
 	setenv("WINDOWID", buf, 1);
 
 	signal(SIGCHLD, SIG_DFL);
@@ -1165,9 +1171,7 @@ execsh(void) {
 	signal(SIGTERM, SIG_DFL);
 	signal(SIGALRM, SIG_DFL);
 
-	DEFAULT(envshell, shell);
-	setenv("TERM", termname, 1);
-	args = opt_cmd ? opt_cmd : (char *[]){envshell, "-i", NULL};
+	args = opt_cmd ? opt_cmd : (char *[]){sh, "-i", NULL};
 	execvp(args[0], args);
 	exit(EXIT_FAILURE);
 }