su: do not change to home dir unless -l

Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

5 files changed, 11 insertions, 7 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 5e5c8c7e8..322a28cab 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1286,6 +1286,7 @@ int sd_listen_fds(void);
 #define SETUP_ENV_CHANGEENV (1 << 0)
 #define SETUP_ENV_CLEARENV  (1 << 1)
 #define SETUP_ENV_TO_TMP    (1 << 2)
+#define SETUP_ENV_NO_CHDIR  (1 << 4)
 extern void setup_environment(const char *shell, int flags, const struct passwd *pw) FAST_FUNC;
 extern int correct_password(const struct passwd *pw) FAST_FUNC;
 /* Returns a malloced string */
diff --git a/libbb/setup_environment.c b/libbb/setup_environment.c
index 73229ca6c..4258656fe 100644
--- a/libbb/setup_environment.c
+++ b/libbb/setup_environment.c
@@ -37,9 +37,11 @@ void FAST_FUNC setup_environment(const char *shell, int flags, const struct pass
 
         /* Change the current working directory to be the home directory
          * of the user */
-        if (chdir(pw->pw_dir)) {
-                xchdir((flags & SETUP_ENV_TO_TMP) ? "/tmp" : "/");
-                bb_error_msg("can't chdir to home directory '%s'", pw->pw_dir);
+        if (!(flags & SETUP_ENV_NO_CHDIR)) {
+                if (chdir(pw->pw_dir) != 0) {
+                        bb_error_msg("can't change directory to '%s'", pw->pw_dir);
+                        xchdir((flags & SETUP_ENV_TO_TMP) ? "/tmp" : "/");
+                }
         }
 
         if (flags & SETUP_ENV_CLEARENV) {
diff --git a/libbb/xfuncs_printf.c b/libbb/xfuncs_printf.c
index d8a42ba0b..05aa07ce8 100644
--- a/libbb/xfuncs_printf.c
+++ b/libbb/xfuncs_printf.c
@@ -355,13 +355,13 @@ void FAST_FUNC xsetuid(uid_t uid)
 void FAST_FUNC xchdir(const char *path)
 {
         if (chdir(path))
-                bb_perror_msg_and_die("chdir(%s)", path);
+                bb_perror_msg_and_die("can't change directory to '%s'", path);
 }
 
 void FAST_FUNC xchroot(const char *path)
 {
         if (chroot(path))
-                bb_perror_msg_and_die("can't change root directory to %s", path);
+                bb_perror_msg_and_die("can't change root directory to '%s'", path);
         xchdir("/");
 }
 
diff --git a/loginutils/su.c b/loginutils/su.c
index 57ea738f4..2ec05e125 100644
--- a/loginutils/su.c
+++ b/loginutils/su.c
@@ -131,7 +131,8 @@ int su_main(int argc UNUSED_PARAM, char **argv)
         change_identity(pw);
         setup_environment(opt_shell,
                         ((flags & SU_OPT_l) / SU_OPT_l * SETUP_ENV_CLEARENV)
-                        + (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV),
+                        + (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV)
+                        + (!(flags & SU_OPT_l) * SETUP_ENV_NO_CHDIR),
                         pw);
         IF_SELINUX(set_current_security_context(NULL);)
 
diff --git a/networking/httpd.c b/networking/httpd.c
index 12218a0a3..a942794f5 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -1414,7 +1414,7 @@ static void send_cgi_and_exit(
                 if (script != url) { /* paranoia */
                         *script = '\0';
                         if (chdir(url + 1) != 0) {
-                                bb_perror_msg("chdir(%s)", url + 1);
+                                bb_perror_msg("can't change directory to '%s'", url + 1);
                                 goto error_execing_cgi;
                         }
                         // not needed: *script = '/';