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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 преди 10 години
родител
ревизия
a3549c2eec
променени са 1 файла, в които са добавени 17 реда и са изтрити 13 реда
  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);
 }