From patchwork Fri Mar 21 10:24:21 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Borisov X-Patchwork-Id: 14025201 X-Patchwork-Delegate: paul@paul-moore.com Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C70501F3B8F for ; Fri, 21 Mar 2025 10:24:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742552672; cv=none; b=EtAiscIengjsk03swT6dNKvhnlp9cw8CTtalOUehrx2dWxBdPa7ZDNXAM1+aNkDH/mWyJz0AGT6TJlS5iBGmf7qeBOoHKdlybCgP5sLuUthF/LEjOI5bieB9d3tLP9GMiT4xdr0psmW/GxlWoObjwhIbxNJYt4A+mrSnqQcpjuc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742552672; c=relaxed/simple; bh=3L1k6EZ6HqN4Jr58ja35SAAQN7Ikbs1lTiTV/MxSrZM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G8qJKOnxZ1Xij2cIje6STo4JivBRseWGM2HBuzwnIqkEHZyPnA8zE8Z49H3SE+C4hHifSggyzyBD2utifH7wZgVzFYBpu9aofFPk/eGZHRos5F9ubcq08N5Z29R+Y+SZ6SBttK3VsY86An4NJ1BooPrhnvgDthhQCTuQMSTZSwc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com; spf=pass smtp.mailfrom=suse.com; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.com Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 28C5421A45; Fri, 21 Mar 2025 10:24:29 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 99D3213A2C; Fri, 21 Mar 2025 10:24:28 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 2PZ8Ilw+3WcvLQAAD6G6ig (envelope-from ); Fri, 21 Mar 2025 10:24:28 +0000 From: Nikolay Borisov To: linux-security-module@vger.kernel.org Cc: paul@paul-moore.com, serge@hallyn.com, kees@kernel.org, linux-kernel@vger.kernel.org, kirill.shutemov@linux.intel.com, linux-coco@lists.linux.dev, Nikolay Borisov Subject: [PATCH 2/2] lockdown/kunit: Introduce kunit tests Date: Fri, 21 Mar 2025 12:24:21 +0200 Message-ID: <20250321102422.640271-3-nik.borisov@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250321102422.640271-1-nik.borisov@suse.com> References: <20250321102422.640271-1-nik.borisov@suse.com> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[]; ASN(0.00)[asn:25478, ipnet:::/0, country:RU] X-Spam-Flag: NO X-Spam-Score: -4.00 X-Rspamd-Queue-Id: 28C5421A45 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Level: Add a bunch of tests to ensure lockdown's conversion to bitmap hasn't regressed it. Signed-off-by: Nikolay Borisov --- security/lockdown/Kconfig | 5 +++ security/lockdown/Makefile | 1 + security/lockdown/lockdown.c | 5 ++- security/lockdown/lockdown_test.c | 55 +++++++++++++++++++++++++++++++ 4 files changed, 65 insertions(+), 1 deletion(-) create mode 100644 security/lockdown/lockdown_test.c diff --git a/security/lockdown/Kconfig b/security/lockdown/Kconfig index e84ddf484010..5fb750da1f8c 100644 --- a/security/lockdown/Kconfig +++ b/security/lockdown/Kconfig @@ -6,6 +6,11 @@ config SECURITY_LOCKDOWN_LSM Build support for an LSM that enforces a coarse kernel lockdown behaviour. +config SECURITY_LOCKDOWN_LSM_TEST + tristate "Test lockdown functionality" if !KUNIT_ALL_TESTS + depends on SECURITY_LOCKDOWN_LSM && KUNIT + default KUNIT_ALL_TESTS + config SECURITY_LOCKDOWN_LSM_EARLY bool "Enable lockdown LSM early in init" depends on SECURITY_LOCKDOWN_LSM diff --git a/security/lockdown/Makefile b/security/lockdown/Makefile index e3634b9017e7..f35d90e39f1c 100644 --- a/security/lockdown/Makefile +++ b/security/lockdown/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown.o +obj-$(CONFIG_SECURITY_LOCKDOWN_LSM_TEST) += lockdown_test.o diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index 5014d18c423f..412184121279 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -25,7 +25,10 @@ static const enum lockdown_reason lockdown_levels[] = {LOCKDOWN_NONE, /* * Put the kernel into lock-down mode. */ -static int lock_kernel_down(const char *where, enum lockdown_reason level) +#if !IS_ENABLED(CONFIG_KUNIT) +static +#endif +int lock_kernel_down(const char *where, enum lockdown_reason level) { if (level > LOCKDOWN_CONFIDENTIALITY_MAX) diff --git a/security/lockdown/lockdown_test.c b/security/lockdown/lockdown_test.c new file mode 100644 index 000000000000..0b4184a40111 --- /dev/null +++ b/security/lockdown/lockdown_test.c @@ -0,0 +1,55 @@ +#include +#include + +int lock_kernel_down(const char *where, enum lockdown_reason level); + +static void lockdown_test_invalid_level(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, -EINVAL, lock_kernel_down("TEST", LOCKDOWN_CONFIDENTIALITY_MAX+1)); +} + +static void lockdown_test_depth_locking(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 0, lock_kernel_down("TEST", LOCKDOWN_INTEGRITY_MAX)); + for (int i = 1; i < LOCKDOWN_INTEGRITY_MAX; i++) { + KUNIT_EXPECT_EQ_MSG(test, -EPERM, security_locked_down(i), "at i=%d", i); + } + + KUNIT_EXPECT_EQ(test, -EPERM, security_locked_down(LOCKDOWN_INTEGRITY_MAX)); +} + +static void lockdown_test_individual_level(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 0, lock_kernel_down("TEST", LOCKDOWN_PERF)); + KUNIT_EXPECT_EQ(test, -EPERM, security_locked_down(LOCKDOWN_PERF)); + /* Ensure adjacent levels are untouched */ + KUNIT_EXPECT_EQ(test, 0, security_locked_down(LOCKDOWN_TRACEFS)); + KUNIT_EXPECT_EQ(test, 0, security_locked_down(LOCKDOWN_DBG_READ_KERNEL)); +} + +static void lockdown_test_no_downgrade(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 0, lock_kernel_down("TEST", LOCKDOWN_CONFIDENTIALITY_MAX)); + KUNIT_EXPECT_EQ(test, 0, lock_kernel_down("TEST", LOCKDOWN_INTEGRITY_MAX)); + /* + * Ensure having locked down to a lower leve after a higher level + * lockdown nothing is lost + */ + KUNIT_EXPECT_EQ(test, -EPERM, security_locked_down(LOCKDOWN_TRACEFS)); +} + +static struct kunit_case lockdown_tests[] = { + KUNIT_CASE(lockdown_test_invalid_level), + KUNIT_CASE(lockdown_test_depth_locking), + KUNIT_CASE(lockdown_test_individual_level), + KUNIT_CASE(lockdown_test_no_downgrade), + {} +}; + +static struct kunit_suite lockdown_test_suite = { + .name = "lockdown test", + .test_cases = lockdown_tests, +}; +kunit_test_suite(lockdown_test_suite); + +MODULE_LICENSE("GPL");