libbb/login/su: do not sanitize shell name twice

function                                             old     new   delta
setup_environment                                    191     205     +14
login_main                                          1002     987     -15
su_main                                              474     458     -16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/2 up/down: 14/-31)            Total: -17 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/setup_environment.c b/libbb/setup_environment.c
index a95fbc5bfc4da7dd967fea91720f2c50ecf1619d..73229ca6ceb410790c1843469aefeddd038704d5 100644 (file)
--- a/libbb/setup_environment.c
+++ b/libbb/setup_environment.c
@@ -32,6 +32,9 @@
 
 void FAST_FUNC setup_environment(const char *shell, int flags, const struct passwd *pw)
 {
+       if (!shell || !shell[0])
+               shell = DEFAULT_SHELL;
+
        /* Change the current working directory to be the home directory
         * of the user */
        if (chdir(pw->pw_dir)) {

diff --git a/loginutils/login.c b/loginutils/login.c
index 952b3aadd2c460db3baa908c394320724bf25532..028a099b6556478338d9a05ab90c406a9de86b9a 100644 (file)
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -198,7 +198,6 @@ int login_main(int argc UNUSED_PARAM, char **argv)
        };
        char *fromhost;
        char username[USERNAME_SIZE];
-       const char *shell;
        int run_by_root;
        unsigned opt;
        int count = 0;
@@ -391,10 +390,7 @@ int login_main(int argc UNUSED_PARAM, char **argv)
                run_login_script(pw, full_tty);
 
        change_identity(pw);
-       shell = pw->pw_shell;
-       if (!shell || !shell[0])
-               shell = DEFAULT_SHELL;
-       setup_environment(shell,
+       setup_environment(pw->pw_shell,
                        (!(opt & LOGIN_OPT_p) * SETUP_ENV_CLEARENV) + SETUP_ENV_CHANGEENV,
                        pw);
 
@@ -442,7 +438,7 @@ int login_main(int argc UNUSED_PARAM, char **argv)
        signal(SIGINT, SIG_DFL);
 
        /* Exec login shell with no additional parameters */
-       run_shell(shell, 1, NULL, NULL);
+       run_shell(pw->pw_shell, 1, NULL, NULL);
 
        /* return EXIT_FAILURE; - not reached */
 }

diff --git a/loginutils/su.c b/loginutils/su.c
index db303af6dfc79620ac91b7d7e778b29f374a4c39..72dd0f06f0b6a59ed1fd2885177aac8c25af4deb 100644 (file)
--- a/loginutils/su.c
+++ b/loginutils/su.c
@@ -114,20 +114,14 @@ int su_main(int argc UNUSED_PARAM, char **argv)
                opt_shell = getenv("SHELL");
        }
 
-       /* Make sure pw->pw_shell is non-NULL.  It may be NULL when NEW_USER
-        * is a username that is retrieved via NIS (YP), that doesn't have
-        * a default shell listed.  */
-       if (!pw->pw_shell || !pw->pw_shell[0])
-               pw->pw_shell = (char *)DEFAULT_SHELL;
-
 #if ENABLE_FEATURE_SU_CHECKS_SHELLS
-       if (opt_shell && cur_uid != 0 && restricted_shell(pw->pw_shell)) {
+       if (opt_shell && cur_uid != 0 && pw->pw_shell && restricted_shell(pw->pw_shell)) {
                /* The user being su'd to has a nonstandard shell, and so is
                 * probably a uucp account or has restricted access.  Don't
                 * compromise the account by allowing access with a standard
                 * shell.  */
                bb_error_msg("using restricted shell");
-               opt_shell = NULL;
+               opt_shell = NULL; /* ignore -s PROG */
        }
        /* else: user can run whatever he wants via "su -s PROG USER".
         * This is safe since PROG is run under user's uid/gid. */