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systemd: Fix CVE-2023-26604

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Below patch files to fix CVE-2023-26604
CVE-2023-26604-1.patch, CVE-2023-26604-2.patch and
CVE-2023-26604-3.patch and CVE-2023-26604-4.patch

make pager secure when under euid is changed or explicitly
requested

Reference:
CVE-2023-26604-1.patch:
612ebf6c91
CVE-2023-26604-2.patch:
1b5b507cd2
CVE-2023-26604-3.patch:
0a42426d79
CVE-2023-26604-4.patch:
b8f736b30e

(From OE-Core rev: 7880eb801dcee44a9e8920d249057492d1de6b12)

Signed-off-by: rajmohan r <rajmohan.r@kpit.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
This commit is contained in:
rajmohan r
2023-04-19 16:04:55 +05:30
committed by Steve Sakoman
parent 20c932eb01
commit afb4425be9
5 changed files with 597 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

115
meta/recipes-core/systemd/systemd/CVE-2023-26604-1.patch Normal file
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@@ -0,0 +1,115 @@
From 612ebf6c913dd0e4197c44909cb3157f5c51a2f0 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 31 Aug 2020 19:37:13 +0200
Subject: [PATCH] pager: set $LESSSECURE whenver we invoke a pager
Some extra safety when invoked via "sudo". With this we address a
genuine design flaw of sudo, and we shouldn't need to deal with this.
But it's still a good idea to disable this surface given how exotic it
is.
Prompted by #5666
CVE: CVE-2023-26604
Upstream-Status: Backport [https://github.com/systemd/systemd/pull/17270/commits/612ebf6c913dd0e4197c44909cb3157f5c51a2f0]
Comments: Hunk not refreshed
Signed-off-by: rajmohan r <rajmohan.r@kpit.com>
---
man/less-variables.xml | 9 +++++++++
man/systemctl.xml | 1 +
man/systemd.xml | 1 +
src/shared/pager.c | 23 +++++++++++++++++++++--
4 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/man/less-variables.xml b/man/less-variables.xml
index 08e513c99f8e..c52511ca8e18 100644
--- a/man/less-variables.xml
+++ b/man/less-variables.xml
@@ -64,6 +64,15 @@
the invoking terminal is determined to be UTF-8 compatible).</para></listitem>
</varlistentry>
+ <varlistentry id='lesssecure'>
+ <term><varname>$SYSTEMD_LESSSECURE</varname></term>
+
+ <listitem><para>Takes a boolean argument. Overrides the <varname>$LESSSECURE</varname> environment
+ variable when invoking the pager, which controls the "secure" mode of less (which disables commands
+ such as <literal>|</literal> which allow to easily shell out to external command lines). By default
+ less secure mode is enabled, with this setting it may be disabled.</para></listitem>
+ </varlistentry>
+
<varlistentry id='colors'>
<term><varname>$SYSTEMD_COLORS</varname></term>
diff --git a/man/systemctl.xml b/man/systemctl.xml
index 1c5502883700..a3f0c3041a57 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -2240,6 +2240,7 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
<xi:include href="less-variables.xml" xpointer="pager"/>
<xi:include href="less-variables.xml" xpointer="less"/>
<xi:include href="less-variables.xml" xpointer="lesscharset"/>
+ <xi:include href="less-variables.xml" xpointer="lesssecure"/>
<xi:include href="less-variables.xml" xpointer="colors"/>
<xi:include href="less-variables.xml" xpointer="urlify"/>
</refsect1>
diff --git a/man/systemd.xml b/man/systemd.xml
index a9040545c2ab..c92cfef77689 100644
--- a/man/systemd.xml
+++ b/man/systemd.xml
@@ -692,6 +692,7 @@
<xi:include href="less-variables.xml" xpointer="pager"/>
<xi:include href="less-variables.xml" xpointer="less"/>
<xi:include href="less-variables.xml" xpointer="lesscharset"/>
+ <xi:include href="less-variables.xml" xpointer="lesssecure"/>
<xi:include href="less-variables.xml" xpointer="colors"/>
<xi:include href="less-variables.xml" xpointer="urlify"/>
diff --git a/src/shared/pager.c b/src/shared/pager.c
index e03be6d23b2d..9c21881241f5 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -9,6 +9,7 @@
#include <unistd.h>
#include "copy.h"
+#include "env-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "io-util.h"
@@ -152,8 +153,7 @@ int pager_open(PagerFlags flags) {
_exit(EXIT_FAILURE);
}
- /* Initialize a good charset for less. This is
- * particularly important if we output UTF-8
+ /* Initialize a good charset for less. This is particularly important if we output UTF-8
* characters. */
less_charset = getenv("SYSTEMD_LESSCHARSET");
if (!less_charset && is_locale_utf8())
@@ -164,6 +164,25 @@ int pager_open(PagerFlags flags) {
_exit(EXIT_FAILURE);
}
+ /* People might invoke us from sudo, don't needlessly allow less to be a way to shell out
+ * privileged stuff. */
+ r = getenv_bool("SYSTEMD_LESSSECURE");
+ if (r == 0) { /* Remove env var if off */
+ if (unsetenv("LESSSECURE") < 0) {
+ log_error_errno(errno, "Failed to uset environment variable LESSSECURE: %m");
+ _exit(EXIT_FAILURE);
+ }
+ } else {
+ /* Set env var otherwise */
+ if (r < 0)
+ log_warning_errno(r, "Unable to parse $SYSTEMD_LESSSECURE, ignoring: %m");
+
+ if (setenv("LESSSECURE", "1", 1) < 0) {
+ log_error_errno(errno, "Failed to set environment variable LESSSECURE: %m");
+ _exit(EXIT_FAILURE);
+ }
+ }
+
if (pager_args) {
r = loop_write(exe_name_pipe[1], pager_args[0], strlen(pager_args[0]) + 1, false);
if (r < 0) {

264
meta/recipes-core/systemd/systemd/CVE-2023-26604-2.patch Normal file
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@@ -0,0 +1,264 @@
From 1b5b507cd2d1d7a2b053151abb548475ad9c5c3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Mon, 12 Oct 2020 18:57:32 +0200
Subject: [PATCH] test-login: always test sd_pid_get_owner_uid(), modernize
A long time some function only worked when in a session, and the test
didn't execute them when sd_pid_get_session() failed. Let's always call
them to increase coverage.
While at it, let's test for ==0 not >=0 where we don't expect the function
to return anything except 0 or error.
CVE: CVE-2023-26604
Upstream-Status: Backport [https://github.com/systemd/systemd/pull/17270/commits/1b5b507cd2d1d7a2b053151abb548475ad9c5c3b.patch]
Comments: Hunk not refreshed
Signed-off-by: rajmohan r <rajmohan.r@kpit.com>
---
src/libsystemd/sd-login/test-login.c | 131 ++++++++++++++-------------
1 file changed, 70 insertions(+), 61 deletions(-)
diff --git a/src/libsystemd/sd-login/test-login.c b/src/libsystemd/sd-login/test-login.c
index c0c77e04714b..0494fc77ba18 100644
--- a/src/libsystemd/sd-login/test-login.c
+++ b/src/libsystemd/sd-login/test-login.c
@@ -5,21 +5,22 @@
#include "sd-login.h"
#include "alloc-util.h"
+#include "errno-list.h"
#include "fd-util.h"
#include "format-util.h"
#include "log.h"
#include "string-util.h"
#include "strv.h"
#include "time-util.h"
-#include "util.h"
+#include "user-util.h"
static char* format_uids(char **buf, uid_t* uids, int count) {
- int pos = 0, k, inc;
+ int pos = 0, inc;
size_t size = (DECIMAL_STR_MAX(uid_t) + 1) * count + 1;
assert_se(*buf = malloc(size));
- for (k = 0; k < count; k++) {
+ for (int k = 0; k < count; k++) {
sprintf(*buf + pos, "%s"UID_FMT"%n", k > 0 ? " " : "", uids[k], &inc);
pos += inc;
}
@@ -30,6 +31,10 @@ static char* format_uids(char **buf, uid_t* uids, int count) {
return *buf;
}
+static const char *e(int r) {
+ return r == 0 ? "OK" : errno_to_name(r);
+}
+
static void test_login(void) {
_cleanup_close_pair_ int pair[2] = { -1, -1 };
_cleanup_free_ char *pp = NULL, *qq = NULL,
@@ -39,65 +44,71 @@ static void test_login(void) {
*seat = NULL, *session = NULL,
*unit = NULL, *user_unit = NULL, *slice = NULL;
int r;
- uid_t u, u2;
- char *t, **seats, **sessions;
+ uid_t u, u2 = UID_INVALID;
+ char *t, **seats = NULL, **sessions = NULL;
r = sd_pid_get_unit(0, &unit);
- assert_se(r >= 0 || r == -ENODATA);
- log_info("sd_pid_get_unit(0, …) → \"%s\"", strna(unit));
+ log_info("sd_pid_get_unit(0, …) → %s / \"%s\"", e(r), strnull(unit));
+ assert_se(IN_SET(r, 0, -ENODATA));
r = sd_pid_get_user_unit(0, &user_unit);
- assert_se(r >= 0 || r == -ENODATA);
- log_info("sd_pid_get_user_unit(0, …) → \"%s\"", strna(user_unit));
+ log_info("sd_pid_get_user_unit(0, …) → %s / \"%s\"", e(r), strnull(user_unit));
+ assert_se(IN_SET(r, 0, -ENODATA));
r = sd_pid_get_slice(0, &slice);
- assert_se(r >= 0 || r == -ENODATA);
- log_info("sd_pid_get_slice(0, …) → \"%s\"", strna(slice));
+ log_info("sd_pid_get_slice(0, …) → %s / \"%s\"", e(r), strnull(slice));
+ assert_se(IN_SET(r, 0, -ENODATA));
+
+ r = sd_pid_get_owner_uid(0, &u2);
+ log_info("sd_pid_get_owner_uid(0, …) → %s / "UID_FMT, e(r), u2);
+ assert_se(IN_SET(r, 0, -ENODATA));
r = sd_pid_get_session(0, &session);
- if (r < 0) {
- log_warning_errno(r, "sd_pid_get_session(0, …): %m");
- if (r == -ENODATA)
- log_info("Seems we are not running in a session, skipping some tests.");
- } else {
- log_info("sd_pid_get_session(0, …) → \"%s\"", session);
-
- assert_se(sd_pid_get_owner_uid(0, &u2) == 0);
- log_info("sd_pid_get_owner_uid(0, …) → "UID_FMT, u2);
-
- assert_se(sd_pid_get_cgroup(0, &cgroup) == 0);
- log_info("sd_pid_get_cgroup(0, …) → \"%s\"", cgroup);
-
- r = sd_uid_get_display(u2, &display_session);
- assert_se(r >= 0 || r == -ENODATA);
- log_info("sd_uid_get_display("UID_FMT", …) → \"%s\"",
- u2, strnull(display_session));
-
- assert_se(socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == 0);
- sd_peer_get_session(pair[0], &pp);
- sd_peer_get_session(pair[1], &qq);
- assert_se(streq_ptr(pp, qq));
-
- r = sd_uid_get_sessions(u2, false, &sessions);
+ log_info("sd_pid_get_session(0, …) → %s / \"%s\"", e(r), strnull(session));
+
+ r = sd_pid_get_cgroup(0, &cgroup);
+ log_info("sd_pid_get_cgroup(0, …) → %s / \"%s\"", e(r), strnull(cgroup));
+ assert_se(r == 0);
+
+ r = sd_uid_get_display(u2, &display_session);
+ log_info("sd_uid_get_display("UID_FMT", …) → %s / \"%s\"", u2, e(r), strnull(display_session));
+ if (u2 == UID_INVALID)
+ assert_se(r == -EINVAL);
+ else
+ assert_se(IN_SET(r, 0, -ENODATA));
+
+ assert_se(socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == 0);
+ sd_peer_get_session(pair[0], &pp);
+ sd_peer_get_session(pair[1], &qq);
+ assert_se(streq_ptr(pp, qq));
+
+ r = sd_uid_get_sessions(u2, false, &sessions);
+ assert_se(t = strv_join(sessions, " "));
+ log_info("sd_uid_get_sessions("UID_FMT", …) → %s \"%s\"", u2, e(r), t);
+ if (u2 == UID_INVALID)
+ assert_se(r == -EINVAL);
+ else {
assert_se(r >= 0);
assert_se(r == (int) strv_length(sessions));
- assert_se(t = strv_join(sessions, " "));
- strv_free(sessions);
- log_info("sd_uid_get_sessions("UID_FMT", …) → [%i] \"%s\"", u2, r, t);
- free(t);
+ }
+ sessions = strv_free(sessions);
+ free(t);
- assert_se(r == sd_uid_get_sessions(u2, false, NULL));
+ assert_se(r == sd_uid_get_sessions(u2, false, NULL));
- r = sd_uid_get_seats(u2, false, &seats);
+ r = sd_uid_get_seats(u2, false, &seats);
+ assert_se(t = strv_join(seats, " "));
+ log_info("sd_uid_get_seats("UID_FMT", …) → %s \"%s\"", u2, e(r), t);
+ if (u2 == UID_INVALID)
+ assert_se(r == -EINVAL);
+ else {
assert_se(r >= 0);
assert_se(r == (int) strv_length(seats));
- assert_se(t = strv_join(seats, " "));
- strv_free(seats);
- log_info("sd_uid_get_seats("UID_FMT", …) → [%i] \"%s\"", u2, r, t);
- free(t);
-
- assert_se(r == sd_uid_get_seats(u2, false, NULL));
}
+ seats = strv_free(seats);
+ free(t);
+
+ assert_se(r == sd_uid_get_seats(u2, false, NULL));
if (session) {
r = sd_session_is_active(session);
@@ -109,7 +120,7 @@ static void test_login(void) {
log_info("sd_session_is_remote(\"%s\") → %s", session, yes_no(r));
r = sd_session_get_state(session, &state);
- assert_se(r >= 0);
+ assert_se(r == 0);
log_info("sd_session_get_state(\"%s\") → \"%s\"", session, state);
assert_se(sd_session_get_uid(session, &u) >= 0);
@@ -123,16 +134,16 @@ static void test_login(void) {
log_info("sd_session_get_class(\"%s\") → \"%s\"", session, class);
r = sd_session_get_display(session, &display);
- assert_se(r >= 0 || r == -ENODATA);
+ assert_se(IN_SET(r, 0, -ENODATA));
log_info("sd_session_get_display(\"%s\") → \"%s\"", session, strna(display));
r = sd_session_get_remote_user(session, &remote_user);
- assert_se(r >= 0 || r == -ENODATA);
+ assert_se(IN_SET(r, 0, -ENODATA));
log_info("sd_session_get_remote_user(\"%s\") → \"%s\"",
session, strna(remote_user));
r = sd_session_get_remote_host(session, &remote_host);
- assert_se(r >= 0 || r == -ENODATA);
+ assert_se(IN_SET(r, 0, -ENODATA));
log_info("sd_session_get_remote_host(\"%s\") → \"%s\"",
session, strna(remote_host));
@@ -161,7 +172,7 @@ static void test_login(void) {
assert_se(r == -ENODATA);
}
- assert_se(sd_uid_get_state(u, &state2) >= 0);
+ assert_se(sd_uid_get_state(u, &state2) == 0);
log_info("sd_uid_get_state("UID_FMT", …) → %s", u, state2);
}
@@ -173,11 +184,11 @@ static void test_login(void) {
assert_se(sd_uid_is_on_seat(u, 0, seat) > 0);
r = sd_seat_get_active(seat, &session2, &u2);
- assert_se(r >= 0);
+ assert_se(r == 0);
log_info("sd_seat_get_active(\"%s\", …) → \"%s\", "UID_FMT, seat, session2, u2);
r = sd_uid_is_on_seat(u, 1, seat);
- assert_se(r >= 0);
+ assert_se(IN_SET(r, 0, 1));
assert_se(!!r == streq(session, session2));
r = sd_seat_get_sessions(seat, &sessions, &uids, &n);
@@ -185,8 +196,8 @@ static void test_login(void) {
assert_se(r == (int) strv_length(sessions));
assert_se(t = strv_join(sessions, " "));
strv_free(sessions);
- log_info("sd_seat_get_sessions(\"%s\", …) → %i, \"%s\", [%i] {%s}",
- seat, r, t, n, format_uids(&buf, uids, n));
+ log_info("sd_seat_get_sessions(\"%s\", …) → %s, \"%s\", [%u] {%s}",
+ seat, e(r), t, n, format_uids(&buf, uids, n));
free(t);
assert_se(sd_seat_get_sessions(seat, NULL, NULL, NULL) == r);
@@ -204,7 +215,7 @@ static void test_login(void) {
r = sd_seat_get_active(NULL, &t, NULL);
assert_se(IN_SET(r, 0, -ENODATA));
- log_info("sd_seat_get_active(NULL, …) (active session on current seat) → %s", strnull(t));
+ log_info("sd_seat_get_active(NULL, …) (active session on current seat) → %s / \"%s\"", e(r), strnull(t));
free(t);
r = sd_get_sessions(&sessions);
@@ -244,13 +255,11 @@ static void test_login(void) {
static void test_monitor(void) {
sd_login_monitor *m = NULL;
- unsigned n;
int r;
- r = sd_login_monitor_new("session", &m);
- assert_se(r >= 0);
+ assert_se(sd_login_monitor_new("session", &m) == 0);
- for (n = 0; n < 5; n++) {
+ for (unsigned n = 0; n < 5; n++) {
struct pollfd pollfd = {};
usec_t timeout, nw;

182
meta/recipes-core/systemd/systemd/CVE-2023-26604-3.patch Normal file
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@@ -0,0 +1,182 @@
From 0a42426d797406b4b01a0d9c13bb759c2629d108 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Wed, 7 Oct 2020 11:15:05 +0200
Subject: [PATCH] pager: make pager secure when under euid is changed or
explicitly requested
The variable is renamed to SYSTEMD_PAGERSECURE (because it's not just about
less now), and we automatically enable secure mode in certain cases, but not
otherwise.
This approach is more nuanced, but should provide a better experience for
users:
- Previusly we would set LESSSECURE=1 and trust the pager to make use of
it. But this has an effect only on less. We need to not start pagers which
are insecure when in secure mode. In particular more is like that and is a
very popular pager.
- We don't enable secure mode always, which means that those other pagers can
reasonably used.
- We do the right thing by default, but the user has ultimate control by
setting SYSTEMD_PAGERSECURE.
Fixes #5666.
v2:
- also check $PKEXEC_UID
v3:
- use 'sd_pid_get_owner_uid() != geteuid()' as the condition
CVE: CVE-2023-26604
Upstream-Status: Backport [https://github.com/systemd/systemd/pull/17270/commits/0a42426d797406b4b01a0d9c13bb759c2629d108]
Comments: Hunk refreshed
Signed-off-by: rajmohan r <rajmohan.r@kpit.com>
---
man/less-variables.xml | 30 +++++++++++++++----
src/shared/pager.c | 63 ++++++++++++++++++++++++++-------------
2 files changed, 66 insertions(+), 27 deletions(-)
diff --git a/man/less-variables.xml b/man/less-variables.xml
index c52511c..049e9f7 100644
--- a/man/less-variables.xml
+++ b/man/less-variables.xml
@@ -65,12 +65,30 @@
</varlistentry>
<varlistentry id='lesssecure'>
- <term><varname>$SYSTEMD_LESSSECURE</varname></term>
-
- <listitem><para>Takes a boolean argument. Overrides the <varname>$LESSSECURE</varname> environment
- variable when invoking the pager, which controls the "secure" mode of less (which disables commands
- such as <literal>|</literal> which allow to easily shell out to external command lines). By default
- less secure mode is enabled, with this setting it may be disabled.</para></listitem>
+ <term><varname>$SYSTEMD_PAGERSECURE</varname></term>
+
+ <listitem><para>Takes a boolean argument. When true, the "secure" mode of the pager is enabled; if
+ false, disabled. If <varname>$SYSTEMD_PAGERSECURE</varname> is not set at all, secure mode is enabled
+ if the effective UID is not the same as the owner of the login session, see <citerefentry
+ project='man-pages'><refentrytitle>geteuid</refentrytitle><manvolnum>2</manvolnum></citerefentry> and
+ <citerefentry><refentrytitle>sd_pid_get_owner_uid</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ In secure mode, <option>LESSSECURE=1</option> will be set when invoking the pager, and the pager shall
+ disable commands that open or create new files or start new subprocesses. When
+ <varname>$SYSTEMD_PAGERSECURE</varname> is not set at all, pagers which are not known to implement
+ secure mode will not be used. (Currently only
+ <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry> implements
+ secure mode.)</para>
+
+ <para>Note: when commands are invoked with elevated privileges, for example under <citerefentry
+ project='man-pages'><refentrytitle>sudo</refentrytitle><manvolnum>8</manvolnum></citerefentry> or
+ <citerefentry
+ project='die-net'><refentrytitle>pkexec</refentrytitle><manvolnum>1</manvolnum></citerefentry>, care
+ must be taken to ensure that unintended interactive features are not enabled. "Secure" mode for the
+ pager may be enabled automatically as describe above. Setting <varname>SYSTEMD_PAGERSECURE=0</varname>
+ or not removing it from the inherited environment allows the user to invoke arbitrary commands. Note
+ that if the <varname>$SYSTEMD_PAGER</varname> or <varname>$PAGER</varname> variables are to be
+ honoured, <varname>$SYSTEMD_PAGERSECURE</varname> must be set too. It might be reasonable to completly
+ disable the pager using <option>--no-pager</option> instead.</para></listitem>
</varlistentry>
<varlistentry id='colors'>
diff --git a/src/shared/pager.c b/src/shared/pager.c
index a3b6576..a72d9ea 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -8,6 +8,8 @@
#include <sys/prctl.h>
#include <unistd.h>
+#include "sd-login.h"
+
#include "copy.h"
#include "env-util.h"
#include "fd-util.h"
@@ -164,25 +166,42 @@ int pager_open(PagerFlags flags) {
}
/* People might invoke us from sudo, don't needlessly allow less to be a way to shell out
- * privileged stuff. */
- r = getenv_bool("SYSTEMD_LESSSECURE");
- if (r == 0) { /* Remove env var if off */
- if (unsetenv("LESSSECURE") < 0) {
- log_error_errno(errno, "Failed to uset environment variable LESSSECURE: %m");
- _exit(EXIT_FAILURE);
- }
- } else {
- /* Set env var otherwise */
+ * privileged stuff. If the user set $SYSTEMD_PAGERSECURE, trust their configuration of the
+ * pager. If they didn't, use secure mode when under euid is changed. If $SYSTEMD_PAGERSECURE
+ * wasn't explicitly set, and we autodetect the need for secure mode, only use the pager we
+ * know to be good. */
+ int use_secure_mode = getenv_bool("SYSTEMD_PAGERSECURE");
+ bool trust_pager = use_secure_mode >= 0;
+ if (use_secure_mode == -ENXIO) {
+ uid_t uid;
+
+ r = sd_pid_get_owner_uid(0, &uid);
if (r < 0)
- log_warning_errno(r, "Unable to parse $SYSTEMD_LESSSECURE, ignoring: %m");
+ log_debug_errno(r, "sd_pid_get_owner_uid() failed, enabling pager secure mode: %m");
- if (setenv("LESSSECURE", "1", 1) < 0) {
- log_error_errno(errno, "Failed to set environment variable LESSSECURE: %m");
- _exit(EXIT_FAILURE);
- }
+ use_secure_mode = r < 0 || uid != geteuid();
+
+ } else if (use_secure_mode < 0) {
+ log_warning_errno(use_secure_mode, "Unable to parse $SYSTEMD_PAGERSECURE, assuming true: %m");
+ use_secure_mode = true;
}
- if (pager_args) {
+ /* We generally always set variables used by less, even if we end up using a different pager.
+ * They shouldn't hurt in any case, and ideally other pagers would look at them too. */
+ if (use_secure_mode)
+ r = setenv("LESSSECURE", "1", 1);
+ else
+ r = unsetenv("LESSSECURE");
+ if (r < 0) {
+ log_error_errno(errno, "Failed to adjust environment variable LESSSECURE: %m");
+ _exit(EXIT_FAILURE);
+ }
+
+ if (trust_pager && pager_args) { /* The pager config might be set globally, and we cannot
+ * know if the user adjusted it to be appropriate for the
+ * secure mode. Thus, start the pager specified through
+ * envvars only when $SYSTEMD_PAGERSECURE was explicitly set
+ * as well. */
r = loop_write(exe_name_pipe[1], pager_args[0], strlen(pager_args[0]) + 1, false);
if (r < 0) {
log_error_errno(r, "Failed to write pager name to socket: %m");
@@ -194,13 +213,14 @@ int pager_open(PagerFlags flags) {
"Failed to execute '%s', using fallback pagers: %m", pager_args[0]);
}
- /* Debian's alternatives command for pagers is
- * called 'pager'. Note that we do not call
- * sensible-pagers here, since that is just a
- * shell script that implements a logic that
- * is similar to this one anyway, but is
- * Debian-specific. */
+ /* Debian's alternatives command for pagers is called 'pager'. Note that we do not call
+ * sensible-pagers here, since that is just a shell script that implements a logic that is
+ * similar to this one anyway, but is Debian-specific. */
FOREACH_STRING(exe, "pager", "less", "more") {
+ /* Only less implements secure mode right now. */
+ if (use_secure_mode && !streq(exe, "less"))
+ continue;
+
r = loop_write(exe_name_pipe[1], exe, strlen(exe) + 1, false);
if (r < 0) {
log_error_errno(r, "Failed to write pager name to socket: %m");
@@ -211,6 +231,7 @@ int pager_open(PagerFlags flags) {
"Failed to execute '%s', using next fallback pager: %m", exe);
}
+ /* Our builtin is also very secure. */
r = loop_write(exe_name_pipe[1], "(built-in)", strlen("(built-in)") + 1, false);
if (r < 0) {
log_error_errno(r, "Failed to write pager name to socket: %m");

32
meta/recipes-core/systemd/systemd/CVE-2023-26604-4.patch Normal file
View File

@@ -0,0 +1,32 @@
From b8f736b30e20a2b44e7c34bb4e43b0d97ae77e3c Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 15 Oct 2020 10:54:48 +0200
Subject: [PATCH] pager: lets check SYSTEMD_PAGERSECURE with secure_getenv()
I can't think of any real vulnerability about this, but it still feels
better to check a variable with "secure" in its name with
secure_getenv() rather than plain getenv().
Paranoia FTW!
CVE: CVE-2023-26604
Upstream-Status: Backport [https://github.com/systemd/systemd/pull/17359/commits/b8f736b30e20a2b44e7c34bb4e43b0d97ae77e3c]
Comments: Hunk refreshed
Signed-off-by: rajmohan r <rajmohan.r@kpit.com>
---
src/shared/pager.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/shared/pager.c b/src/shared/pager.c
index a72d9ea..250519c 100644
--- a/src/shared/pager.c
+++ b/src/shared/pager.c
@@ -170,7 +170,7 @@ int pager_open(PagerFlags flags) {
* pager. If they didn't, use secure mode when under euid is changed. If $SYSTEMD_PAGERSECURE
* wasn't explicitly set, and we autodetect the need for secure mode, only use the pager we
* know to be good. */
- int use_secure_mode = getenv_bool("SYSTEMD_PAGERSECURE");
+ int use_secure_mode = getenv_bool_secure("SYSTEMD_PAGERSECURE");
bool trust_pager = use_secure_mode >= 0;
if (use_secure_mode == -ENXIO) {
uid_t uid;

4
meta/recipes-core/systemd/systemd_244.5.bb
View File

@@ -35,6 +35,10 @@ SRC_URI += "file://touchscreen.rules \
file://CVE-2021-3997-2.patch \
file://CVE-2021-3997-3.patch \
file://CVE-2022-3821.patch \
file://CVE-2023-26604-1.patch \
file://CVE-2023-26604-2.patch \
file://CVE-2023-26604-3.patch \
file://CVE-2023-26604-4.patch \
"
# patches needed by musl