X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=loginutils%2Fsulogin.c;h=77eff9f8dc415b0395a4474c59eb17f1d54484a8;hb=9f5a577a3241597cb5e7ba9f6df33c2e3c440e44;hp=36b10fbc4f05271fa17b99084ae4c198b986f10e;hpb=b6adbf1be29841501cc49917249e85f273e1df7c;p=oweals%2Fbusybox.git

diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
index 36b10fbc4..77eff9f8d 100644
--- a/loginutils/sulogin.c
+++ b/loginutils/sulogin.c
@@ -5,76 +5,54 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include <syslog.h>
-
 #include "libbb.h"
+#include <syslog.h>
 
-static const char * const forbid[] = {
-	"ENV",
-	"BASH_ENV",
-	"HOME",
-	"IFS",
-	"PATH",
-	"SHELL",
-	"LD_LIBRARY_PATH",
-	"LD_PRELOAD",
-	"LD_TRACE_LOADED_OBJECTS",
-	"LD_BIND_NOW",
-	"LD_AOUT_LIBRARY_PATH",
-	"LD_AOUT_PRELOAD",
-	"LD_NOWARN",
-	"LD_KEEPDIR",
-	(char *) 0
-};
-
-
-static void catchalarm(int ATTRIBUTE_UNUSED junk)
-{
-	exit(EXIT_FAILURE);
-}
+//static void catchalarm(int UNUSED_PARAM junk)
+//{
+//	exit(EXIT_FAILURE);
+//}
 
 
-int sulogin_main(int argc, char **argv);
-int sulogin_main(int argc, char **argv)
+int sulogin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int sulogin_main(int argc UNUSED_PARAM, char **argv)
 {
 	char *cp;
 	int timeout = 0;
-	char *timeout_arg;
-	const char * const *p;
 	struct passwd *pwd;
 	const char *shell;
 #if ENABLE_FEATURE_SHADOWPASSWDS
 	/* Using _r function to avoid pulling in static buffers */
 	char buffer[256];
 	struct spwd spw;
-	struct spwd *result;
 #endif
 
 	logmode = LOGMODE_BOTH;
 	openlog(applet_name, 0, LOG_AUTH);
 
-	if (getopt32(argc, argv, "t:", &timeout_arg)) {
-		timeout = xatoi_u(timeout_arg);
-	}
+	opt_complementary = "t+"; /* -t N */
+	getopt32(argv, "t:", &timeout);
+	argv += optind;
 
-	if (argv[optind]) {
+	if (argv[0]) {
 		close(0);
 		close(1);
-		dup(xopen(argv[optind], O_RDWR));
+		dup(xopen(argv[0], O_RDWR));
 		close(2);
 		dup(0);
 	}
 
+	/* Malicious use like "sulogin /dev/sda"? */
 	if (!isatty(0) || !isatty(1) || !isatty(2)) {
 		logmode = LOGMODE_SYSLOG;
 		bb_error_msg_and_die("not a tty");
 	}
 
-	/* Clear out anything dangerous from the environment */
-	for (p = forbid; *p; p++)
-		unsetenv(*p);
+	/* Clear dangerous stuff, set PATH */
+	sanitize_env_if_suid();
 
-	signal(SIGALRM, catchalarm);
+// bb_ask() already handles this
+//	signal(SIGALRM, catchalarm);
 
 	pwd = getpwuid(0);
 	if (!pwd) {
@@ -82,15 +60,24 @@ int sulogin_main(int argc, char **argv)
 	}
 
 #if ENABLE_FEATURE_SHADOWPASSWDS
-	if (getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result)) {
-		goto auth_error;
+	{
+		/* getspnam_r may return 0 yet set result to NULL.
+		 * At least glibc 2.4 does this. Be extra paranoid here. */
+		struct spwd *result = NULL;
+		int r = getspnam_r(pwd->pw_name, &spw, buffer, sizeof(buffer), &result);
+		if (r || !result) {
+			goto auth_error;
+		}
+		pwd->pw_passwd = result->sp_pwdp;
 	}
-	pwd->pw_passwd = spw.sp_pwdp;
 #endif
 
 	while (1) {
+		char *encrypted;
+		int r;
+
 		/* cp points to a static buffer that is zeroed every time */
-		cp = bb_askpass(timeout,
+		cp = bb_ask(STDIN_FILENO, timeout,
 				"Give root password for system maintenance\n"
 				"(or type Control-D for normal startup):");
 
@@ -98,29 +85,33 @@ int sulogin_main(int argc, char **argv)
 			bb_info_msg("Normal startup");
 			return 0;
 		}
-		if (strcmp(pw_encrypt(cp, pwd->pw_passwd), pwd->pw_passwd) == 0) {
+		encrypted = pw_encrypt(cp, pwd->pw_passwd, 1);
+		r = strcmp(encrypted, pwd->pw_passwd);
+		free(encrypted);
+		if (r == 0) {
 			break;
 		}
 		bb_do_delay(FAIL_DELAY);
 		bb_error_msg("login incorrect");
 	}
 	memset(cp, 0, strlen(cp));
-	signal(SIGALRM, SIG_DFL);
+//	signal(SIGALRM, SIG_DFL);
 
 	bb_info_msg("System Maintenance Mode");
 
-	USE_SELINUX(renew_current_security_context());
+	IF_SELINUX(renew_current_security_context());
 
 	shell = getenv("SUSHELL");
-	if (!shell) shell = getenv("sushell");
+	if (!shell)
+		shell = getenv("sushell");
 	if (!shell) {
 		shell = "/bin/sh";
 		if (pwd->pw_shell[0])
 			shell = pwd->pw_shell;
 	}
-	run_shell(shell, 1, 0, 0);
-	/* never returns */
+	/* Exec login shell with no additional parameters. Never returns. */
+	run_shell(shell, 1, NULL, NULL);
 
-auth_error:
-	bb_error_msg_and_die("no password entry for 'root'");
+ auth_error:
+	bb_error_msg_and_die("no password entry for root");
 }