From 0a4c2503e0a6b1bdb34f3fa8f6644250eccbc445 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Fri, 19 Mar 2010 19:28:56 -0400
Subject: [PATCH] Avoid extraneous commandline parsing
Switch to using g_spawn_sync instead of g_spawn_command_line_sync
to avoid the pointless roundtrip through a commandline parser, avoiding
some security pitfalls.
---
src/daemon.c | 46 ++++++++++++++++--------
src/user.c | 115 ++++++++++++++++++++++++++++++++++------------------------
2 files changed, 98 insertions(+), 63 deletions(-)
diff --git a/src/daemon.c b/src/daemon.c
index a962dc3..18a23fe 100644
--- a/src/daemon.c
+++ b/src/daemon.c
@@ -922,7 +922,7 @@ typedef struct {
DBusGMethodInvocation *context;
} ListUserData;
-ListUserData *
+static ListUserData *
list_user_data_new (Daemon *daemon,
DBusGMethodInvocation *context)
{
@@ -1006,11 +1006,10 @@ daemon_create_user_authorized_cb (Daemon *daemon,
{
CreateUserData *cd = data;
User *user;
- gchar *cmdline;
GError *error;
gchar *std_err, *std_out;
gint status;
- const gchar *grouparg;
+ gchar *argv[8];
if (getpwnam (cd->user_name) != NULL) {
throw_error (context, ERROR_USER_EXISTS, "A user with name '%s' already exists", cd->user_name);
@@ -1022,22 +1021,32 @@ daemon_create_user_authorized_cb (Daemon *daemon,
"create user '%s'",
cd->user_name);
+ argv[0] = "/usr/sbin/useradd";
+ argv[1] = "-m";
+ argv[2] = "-c";
+ argv[3] = cd->real_name;
if (cd->account_type == ACCOUNT_TYPE_ADMINISTRATOR) {
- grouparg = "-G desktop_admin_r";
+ argv[4] = "-G";
+ argv[5] = "desktop_admin_r";
+ argv[6] = cd->user_name;
+ argv[7] = NULL;
}
else if (cd->account_type == ACCOUNT_TYPE_STANDARD) {
- grouparg = "-G desktop_user_r";
+ argv[4] = "-G";
+ argv[5] = "desktop_user_r";
+ argv[6] = cd->user_name;
+ argv[7] = NULL;
}
else {
- grouparg = "";
+ argv[4] = cd->user_name;
+ argv[5] = NULL;
}
- cmdline = g_strdup_printf ("/usr/sbin/useradd -m -c '%s' %s %s", cd->real_name, grouparg, cd->user_name);
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1051,7 +1060,6 @@ daemon_create_user_authorized_cb (Daemon *daemon,
return;
}
- g_free (cmdline);
g_free (std_out);
g_free (std_err);
@@ -1099,12 +1107,12 @@ daemon_delete_user_authorized_cb (Daemon *daemon,
{
DeleteUserData *ud = data;
- gchar *cmdline;
GError *error;
gchar *std_err, *std_out;
gint status;
gchar *filename;
struct passwd *pwent;
+ gchar *argv[4];
pwent = getpwuid (ud->uid);
@@ -1118,13 +1126,22 @@ daemon_delete_user_authorized_cb (Daemon *daemon,
"delete user '%s' (%d)",
pwent->pw_name, ud->uid);
- cmdline = g_strdup_printf ("/usr/sbin/userdel %s%s", ud->remove_files ? "-r " : "", pwent->pw_name);
+ argv[0] = "/usr/sbin/userdel";
+ if (ud->remove_files) {
+ argv[1] = "-r";
+ argv[2] = pwent->pw_name;
+ argv[3] = NULL;
+ }
+ else {
+ argv[1] = pwent->pw_name;
+ argv[2] = NULL;
+ }
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1142,7 +1159,6 @@ daemon_delete_user_authorized_cb (Daemon *daemon,
g_remove (filename);
g_free (filename);
- g_free (cmdline);
dbus_g_method_return (context);
}
diff --git a/src/user.c b/src/user.c
index a235411..cfdd16c 100644
--- a/src/user.c
+++ b/src/user.c
@@ -737,20 +737,24 @@ user_change_real_name_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[5];
if (g_strcmp0 (user->real_name, name) != 0) {
daemon_local_log (daemon, context,
"change real name of user '%s' (%d) to '%s'",
user->user_name, user->uid, name);
- cmdline = g_strdup_printf ("/usr/sbin/usermod -c '%s' %s", name, user->user_name);
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = "-c";
+ argv[2] = name;
+ argv[3] = user->user_name;
+ argv[4] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -761,13 +765,11 @@ user_change_real_name_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
g_free (user->real_name);
user->real_name = g_strdup (name);
@@ -831,7 +833,7 @@ user_change_user_name_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[5];
if (g_strcmp0 (user->user_name, name) != 0) {
old_name = g_strdup (user->user_name);
@@ -839,13 +841,17 @@ user_change_user_name_authorized_cb (Daemon *daemon,
"change name of user '%s' (%d) to '%s'",
old_name, user->uid, name);
- cmdline = g_strdup_printf ("/usr/sbin/usermod -l %s %s", name, user->user_name);
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = "-l";
+ argv[2] = name;
+ argv[3] = user->user_name;
+ argv[4] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -856,13 +862,11 @@ user_change_user_name_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
g_free (user->user_name);
user->user_name = g_strdup (name);
@@ -1118,19 +1122,25 @@ user_change_home_dir_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[6];
if (g_strcmp0 (user->home_dir, home_dir) != 0) {
daemon_local_log (daemon, context,
"change home directory of user '%s' (%d) to '%s'",
user->user_name, user->uid, home_dir);
- cmdline = g_strdup_printf ("/usr/sbin/usermod -m -d '%s' %s", home_dir, user->user_name);
+
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = "-m";
+ argv[2] = "-d";
+ argv[3] = home_dir;
+ argv[4] = user->user_name;
+ argv[5] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1141,13 +1151,11 @@ user_change_home_dir_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
g_free (user->home_dir);
user->home_dir = g_strdup (home_dir);
@@ -1159,6 +1167,7 @@ user_change_home_dir_authorized_cb (Daemon *daemon,
dbus_g_method_return (context);
}
+
gboolean
user_set_home_directory (User *user,
const gchar *home_dir,
@@ -1206,20 +1215,24 @@ user_change_shell_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[5];
if (g_strcmp0 (user->shell, shell) != 0) {
daemon_local_log (daemon, context,
"change shell of user '%s' (%d) to '%s'",
user->user_name, user->uid, shell);
- cmdline = g_strdup_printf ("/usr/sbin/usermod -s '%s' %s", shell, user->user_name);
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = "-s";
+ argv[2] = shell;
+ argv[3] = user->user_name;
+ argv[4] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1230,13 +1243,11 @@ user_change_shell_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
g_free (user->shell);
user->shell = g_strdup (shell);
@@ -1475,19 +1486,22 @@ user_change_locked_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[4];
if (user->locked != locked) {
daemon_local_log (daemon, context,
"%s account of user '%s' (%d)",
locked ? "locking" : "unlocking", user->user_name, user->uid);
- cmdline = g_strdup_printf ("/usr/sbin/usermod -%c %s", locked ? 'L' : 'U', user->user_name);
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = locked ? "-L" : "-U";
+ argv[2] = user->user_name;
+ argv[3] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1498,13 +1512,11 @@ user_change_locked_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
user->locked = locked;
@@ -1544,7 +1556,6 @@ user_change_account_type_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
gid_t groups[20];
gint n_groups;
GString *str;
@@ -1552,6 +1563,7 @@ user_change_account_type_authorized_cb (Daemon *daemon,
gid_t desktop_admin_r;
struct group *grp;
gint i;
+ gchar *argv[5];
if (user->account_type != account_type) {
daemon_local_log (daemon, context,
@@ -1596,13 +1608,19 @@ user_change_account_type_authorized_cb (Daemon *daemon,
g_string_truncate (str, str->len - 1);
}
- cmdline = g_strdup_printf ("/usr/sbin/usermod -G %s %s", str->str, user->user_name);
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = "-G";
+ argv[2] = str->str;
+ argv[3] = user->user_name;
+ argv[4] = NULL;
+
+ g_string_free (str, FALSE);
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1613,13 +1631,11 @@ user_change_account_type_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
user->account_type = account_type;
@@ -1664,7 +1680,7 @@ user_change_password_mode_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[4];
if (user->password_mode != mode) {
daemon_local_log (daemon, context,
@@ -1674,13 +1690,16 @@ user_change_password_mode_authorized_cb (Daemon *daemon,
if (mode == PASSWORD_MODE_SET_AT_LOGIN ||
mode == PASSWORD_MODE_NONE) {
- cmdline = g_strdup_printf ("/usr/bin/passwd -d %s", user->user_name);
+ argv[0] = "/usr/bin/passwd";
+ argv[1] = "-d";
+ argv[2] = user->user_name;
+ argv[3] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1691,13 +1710,11 @@ user_change_password_mode_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
g_free (user->password_hint);
user->password_hint = NULL;
@@ -1774,19 +1791,23 @@ user_change_password_authorized_cb (Daemon *daemon,
GError *error;
gint status;
gchar *std_out, *std_err;
- gchar *cmdline;
+ gchar *argv[5];
daemon_local_log (daemon, context,
"set password and hint of user '%s' (%d)",
user->user_name, user->uid);
- cmdline = g_strdup_printf ("/usr/sbin/usermod -p '%s' %s", strings[0], user->user_name);
+ argv[0] = "/usr/sbin/usermod";
+ argv[1] = "-p";
+ argv[2] = strings[0];
+ argv[3] = user->user_name;
+ argv[4] = NULL;
std_out = NULL;
std_err = NULL;
error = NULL;
- if (!g_spawn_command_line_sync (cmdline, &std_out, &std_err, &status, &error)) {
- throw_error (context, ERROR_FAILED, "running '%s' failed: %s", cmdline, error->message);
+ if (!g_spawn_sync (NULL, argv, NULL, 0, NULL, NULL, &std_out, &std_err, &status, &error)) {
+ throw_error (context, ERROR_FAILED, "running '%s' failed: %s", argv[0], error->message);
g_error_free (error);
g_free (std_out);
g_free (std_err);
@@ -1797,13 +1818,11 @@ user_change_password_authorized_cb (Daemon *daemon,
throw_error (context, ERROR_FAILED, "usermod returned an error: %s", std_err);
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
return;
}
g_free (std_out);
g_free (std_err);
- g_free (cmdline);
if (user->password_mode != PASSWORD_MODE_REGULAR) {
user->password_mode = PASSWORD_MODE_REGULAR;
--
1.7.0.1