From 549cb941c5b19909fb00f2bef9c04172ca1c162d Mon Sep 17 00:00:00 2001 From: Ross Burton Date: Tue, 18 Jul 2017 17:04:08 +0100 Subject: systemd: refuse to load units with errors (CVE-2017-1000082) 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 Signed-off-by: Richard Purdie --- ...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 0000000000..80948b2cee --- /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 + +From d8e1310e1ed7b6f122bc7eb8ba061fbd088783c0 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= +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 +--- + 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 e8292ab388..9c533ea4c8 100644 --- a/meta/recipes-core/systemd/systemd_232.bb +++ b/meta/recipes-core/systemd/systemd_232.bb @@ -32,6 +32,7 @@ SRC_URI += " \ file://0020-back-port-233-don-t-use-the-unified-hierarchy-for-the-systemd.patch \ file://0021-build-sys-check-for-lz4-in-the-old-and-new-numbering.patch \ file://0022-parse-util-Do-not-include-unneeded-xlocale.h.patch \ + file://0001-core-load-fragment-refuse-units-with-errors-in-certa.patch \ " SRC_URI_append_qemuall = " file://0001-core-device.c-Change-the-default-device-timeout-to-2.patch" -- cgit 1.2.3-korg