[OE-core] [PATCH][pyro] systemd: refuse to load units with errors (CVE-2017-1000082)
Ross Burton
ross.burton at intel.com
Wed Jul 19 12:34:44 UTC 2017
If a unit has a statement such as User=0day where the username exists but is
strictly speaking invalid, the unit will be started as the root user instead.
Backport a patch from upstream to mitigate this by refusing to start units such
as this.
Signed-off-by: Ross Burton <ross.burton at intel.com>
---
...ragment-refuse-units-with-errors-in-certa.patch | 329 +++++++++++++++++++++
meta/recipes-core/systemd/systemd_232.bb | 1 +
2 files changed, 330 insertions(+)
create mode 100644 meta/recipes-core/systemd/systemd/0001-core-load-fragment-refuse-units-with-errors-in-certa.patch
diff --git a/meta/recipes-core/systemd/systemd/0001-core-load-fragment-refuse-units-with-errors-in-certa.patch b/meta/recipes-core/systemd/systemd/0001-core-load-fragment-refuse-units-with-errors-in-certa.patch
new file mode 100644
index 00000000000..80948b2ceea
--- /dev/null
+++ b/meta/recipes-core/systemd/systemd/0001-core-load-fragment-refuse-units-with-errors-in-certa.patch
@@ -0,0 +1,329 @@
+If a user is created with a strictly-speaking invalid name such as '0day' and a
+unit created to run as that user, systemd rejects the username and runs the unit
+as root.
+
+CVE: CVE-2017-1000082
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton at intel.com>
+
+From d8e1310e1ed7b6f122bc7eb8ba061fbd088783c0 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek at in.waw.pl>
+Date: Thu, 6 Jul 2017 13:28:19 -0400
+Subject: [PATCH] core/load-fragment: refuse units with errors in certain
+ directives
+
+If an error is encountered in any of the Exec* lines, WorkingDirectory,
+SELinuxContext, ApparmorProfile, SmackProcessLabel, Service (in .socket
+units), User, or Group, refuse to load the unit. If the config stanza
+has support, ignore the failure if '-' is present.
+
+For those configuration directives, even if we started the unit, it's
+pretty likely that it'll do something unexpected (like write files
+in a wrong place, or with a wrong context, or run with wrong permissions,
+etc). It seems better to refuse to start the unit and have the admin
+clean up the configuration without giving the service a chance to mess
+up stuff.
+
+Note that all "security" options that restrict what the unit can do
+(Capabilities, AmbientCapabilities, Restrict*, SystemCallFilter, Limit*,
+PrivateDevices, Protect*, etc) are _not_ treated like this. Such options are
+only supplementary, and are not always available depending on the architecture
+and compilation options, so unit authors have to make sure that the service
+runs correctly without them anyway.
+
+Fixes #6237, #6277.
+
+Signed-off-by: Ross Burton <ross.burton at intel.com>
+---
+ src/core/load-fragment.c | 104 ++++++++++++++++++++++++++++------------------
+ src/test/test-unit-file.c | 14 +++----
+ 2 files changed, 70 insertions(+), 48 deletions(-)
+
+diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
+index cbc826809..2047974f4 100644
+--- a/src/core/load-fragment.c
++++ b/src/core/load-fragment.c
+@@ -630,20 +630,28 @@ int config_parse_exec(
+
+ if (isempty(f)) {
+ /* First word is either "-" or "@" with no command. */
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Empty path in command line, ignoring: \"%s\"", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0,
++ "Empty path in command line%s: \"%s\"",
++ ignore ? ", ignoring" : "", rvalue);
++ return ignore ? 0 : -ENOEXEC;
+ }
+ if (!string_is_safe(f)) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path contains special characters, ignoring: %s", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0,
++ "Executable path contains special characters%s: %s",
++ ignore ? ", ignoring" : "", rvalue);
++ return ignore ? 0 : -ENOEXEC;
+ }
+ if (!path_is_absolute(f)) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path is not absolute, ignoring: %s", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0,
++ "Executable path is not absolute%s: %s",
++ ignore ? ", ignoring" : "", rvalue);
++ return ignore ? 0 : -ENOEXEC;
+ }
+ if (endswith(f, "/")) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Executable path specifies a directory, ignoring: %s", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0,
++ "Executable path specifies a directory%s: %s",
++ ignore ? ", ignoring" : "", rvalue);
++ return ignore ? 0 : -ENOEXEC;
+ }
+
+ if (f == firstword) {
+@@ -699,7 +707,7 @@ int config_parse_exec(
+ if (r == 0)
+ break;
+ else if (r < 0)
+- return 0;
++ return ignore ? 0 : -ENOEXEC;
+
+ if (!GREEDY_REALLOC(n, nbufsize, nlen + 2))
+ return log_oom();
+@@ -709,8 +717,10 @@ int config_parse_exec(
+ }
+
+ if (!n || !n[0]) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Empty executable name or zeroeth argument, ignoring: %s", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0,
++ "Empty executable name or zeroeth argument%s: %s",
++ ignore ? ", ignoring" : "", rvalue);
++ return ignore ? 0 : -ENOEXEC;
+ }
+
+ nce = new0(ExecCommand, 1);
+@@ -1315,8 +1325,10 @@ int config_parse_exec_selinux_context(
+
+ r = unit_name_printf(u, rvalue, &k);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %m");
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r,
++ "Failed to resolve specifiers%s: %m",
++ ignore ? ", ignoring" : "");
++ return ignore ? 0 : -ENOEXEC;
+ }
+
+ free(c->selinux_context);
+@@ -1363,8 +1375,10 @@ int config_parse_exec_apparmor_profile(
+
+ r = unit_name_printf(u, rvalue, &k);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %m");
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r,
++ "Failed to resolve specifiers%s: %m",
++ ignore ? ", ignoring" : "");
++ return ignore ? 0 : -ENOEXEC;
+ }
+
+ free(c->apparmor_profile);
+@@ -1411,8 +1425,10 @@ int config_parse_exec_smack_process_label(
+
+ r = unit_name_printf(u, rvalue, &k);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %m");
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r,
++ "Failed to resolve specifiers%s: %m",
++ ignore ? ", ignoring" : "");
++ return ignore ? 0 : -ENOEXEC;
+ }
+
+ free(c->smack_process_label);
+@@ -1630,19 +1646,19 @@ int config_parse_socket_service(
+
+ r = unit_name_printf(UNIT(s), rvalue, &p);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers, ignoring: %s", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve specifiers: %s", rvalue);
++ return -ENOEXEC;
+ }
+
+ if (!endswith(p, ".service")) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Unit must be of type service, ignoring: %s", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0, "Unit must be of type service: %s", rvalue);
++ return -ENOEXEC;
+ }
+
+ r = manager_load_unit(UNIT(s)->manager, p, NULL, &error, &x);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to load unit %s, ignoring: %s", rvalue, bus_error_message(&error, r));
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r, "Failed to load unit %s: %s", rvalue, bus_error_message(&error, r));
++ return -ENOEXEC;
+ }
+
+ unit_ref_set(&s->service, x);
+@@ -1893,13 +1909,13 @@ int config_parse_user_group(
+
+ r = unit_full_printf(u, rvalue, &k);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s: %m", rvalue);
++ return -ENOEXEC;
+ }
+
+ if (!valid_user_group_name_or_id(k)) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID, ignoring: %s", k);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID: %s", k);
++ return -ENOEXEC;
+ }
+
+ n = k;
+@@ -1957,19 +1973,19 @@ int config_parse_user_group_strv(
+ if (r == -ENOMEM)
+ return log_oom();
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Invalid syntax, ignoring: %s", rvalue);
+- break;
++ log_syntax(unit, LOG_ERR, filename, line, r, "Invalid syntax: %s", rvalue);
++ return -ENOEXEC;
+ }
+
+ r = unit_full_printf(u, word, &k);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s, ignoring: %m", word);
+- continue;
++ log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in %s: %m", word);
++ return -ENOEXEC;
+ }
+
+ if (!valid_user_group_name_or_id(k)) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID, ignoring: %s", k);
+- continue;
++ log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid user/group name or numeric ID: %s", k);
++ return -ENOEXEC;
+ }
+
+ r = strv_push(users, k);
+@@ -2128,25 +2144,28 @@ int config_parse_working_directory(
+
+ r = unit_full_printf(u, rvalue, &k);
+ if (r < 0) {
+- log_syntax(unit, LOG_ERR, filename, line, r, "Failed to resolve unit specifiers in working directory path '%s', ignoring: %m", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, r,
++ "Failed to resolve unit specifiers in working directory path '%s'%s: %m",
++ rvalue, missing_ok ? ", ignoring" : "");
++ return missing_ok ? 0 : -ENOEXEC;
+ }
+
+ path_kill_slashes(k);
+
+ if (!utf8_is_valid(k)) {
+ log_syntax_invalid_utf8(unit, LOG_ERR, filename, line, rvalue);
+- return 0;
++ return missing_ok ? 0 : -ENOEXEC;
+ }
+
+ if (!path_is_absolute(k)) {
+- log_syntax(unit, LOG_ERR, filename, line, 0, "Working directory path '%s' is not absolute, ignoring.", rvalue);
+- return 0;
++ log_syntax(unit, LOG_ERR, filename, line, 0,
++ "Working directory path '%s' is not absolute%s.",
++ rvalue, missing_ok ? ", ignoring" : "");
++ return missing_ok ? 0 : -ENOEXEC;
+ }
+
+- free_and_replace(c->working_directory, k);
+-
+ c->working_directory_home = false;
++ free_and_replace(c->working_directory, k);
+ }
+
+ c->working_directory_missing_ok = missing_ok;
+@@ -4228,8 +4247,11 @@ int unit_load_fragment(Unit *u) {
+ return r;
+
+ r = load_from_path(u, k);
+- if (r < 0)
++ if (r < 0) {
++ if (r == -ENOEXEC)
++ log_unit_notice(u, "Unit configuration has fatal error, unit will not be started.");
+ return r;
++ }
+
+ if (u->load_state == UNIT_STUB) {
+ SET_FOREACH(t, u->names, i) {
+diff --git a/src/test/test-unit-file.c b/src/test/test-unit-file.c
+index 12f48bf43..fd797b587 100644
+--- a/src/test/test-unit-file.c
++++ b/src/test/test-unit-file.c
+@@ -146,7 +146,7 @@ static void test_config_parse_exec(void) {
+ r = config_parse_exec(NULL, "fake", 4, "section", 1,
+ "LValue", 0, "/RValue/ argv0 r1",
+ &c, u);
+- assert_se(r == 0);
++ assert_se(r == -ENOEXEC);
+ assert_se(c1->command_next == NULL);
+
+ log_info("/* honour_argv0 */");
+@@ -161,7 +161,7 @@ static void test_config_parse_exec(void) {
+ r = config_parse_exec(NULL, "fake", 3, "section", 1,
+ "LValue", 0, "@/RValue",
+ &c, u);
+- assert_se(r == 0);
++ assert_se(r == -ENOEXEC);
+ assert_se(c1->command_next == NULL);
+
+ log_info("/* no command, whitespace only, reset */");
+@@ -220,7 +220,7 @@ static void test_config_parse_exec(void) {
+ "-@/RValue argv0 r1 ; ; "
+ "/goo/goo boo",
+ &c, u);
+- assert_se(r >= 0);
++ assert_se(r == -ENOEXEC);
+ c1 = c1->command_next;
+ check_execcommand(c1, "/RValue", "argv0", "r1", NULL, true);
+
+@@ -374,7 +374,7 @@ static void test_config_parse_exec(void) {
+ r = config_parse_exec(NULL, "fake", 4, "section", 1,
+ "LValue", 0, path,
+ &c, u);
+- assert_se(r == 0);
++ assert_se(r == -ENOEXEC);
+ assert_se(c1->command_next == NULL);
+ }
+
+@@ -401,21 +401,21 @@ static void test_config_parse_exec(void) {
+ r = config_parse_exec(NULL, "fake", 4, "section", 1,
+ "LValue", 0, "/path\\",
+ &c, u);
+- assert_se(r == 0);
++ assert_se(r == -ENOEXEC);
+ assert_se(c1->command_next == NULL);
+
+ log_info("/* missing ending ' */");
+ r = config_parse_exec(NULL, "fake", 4, "section", 1,
+ "LValue", 0, "/path 'foo",
+ &c, u);
+- assert_se(r == 0);
++ assert_se(r == -ENOEXEC);
+ assert_se(c1->command_next == NULL);
+
+ log_info("/* missing ending ' with trailing backslash */");
+ r = config_parse_exec(NULL, "fake", 4, "section", 1,
+ "LValue", 0, "/path 'foo\\",
+ &c, u);
+- assert_se(r == 0);
++ assert_se(r == -ENOEXEC);
+ assert_se(c1->command_next == NULL);
+
+ log_info("/* invalid space between modifiers */");
+--
+2.11.0
diff --git a/meta/recipes-core/systemd/systemd_232.bb b/meta/recipes-core/systemd/systemd_232.bb
index 398cb46f0d8..e54c723d7f1 100644
--- a/meta/recipes-core/systemd/systemd_232.bb
+++ b/meta/recipes-core/systemd/systemd_232.bb
@@ -33,6 +33,7 @@ SRC_URI += " \
file://0018-check-for-uchar.h-in-configure.patch \
file://0019-socket-util-don-t-fail-if-libc-doesn-t-support-IDN.patch \
file://0020-back-port-233-don-t-use-the-unified-hierarchy-for-the-systemd.patch \
+ file://0001-core-load-fragment-refuse-units-with-errors-in-certa.patch \
"
SRC_URI_append_libc-uclibc = "\
file://0002-units-Prefer-getty-to-agetty-in-console-setup-system.patch \
--
2.11.0
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