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From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net>
To: Christian Brauner <brauner@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Mark Brown <broonie@kernel.org>,
	Sasha Levin <sashal@kernel.org>,
	Sean Christopherson <seanjc@google.com>,
	Shengyu Li <shengyu.li.evgeny@gmail.com>,
	Shuah Khan <shuah@kernel.org>,
	Shuah Khan <skhan@linuxfoundation.org>
Cc: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net>,
	Bagas Sanjaya <bagasdotme@gmail.com>,
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	David Gow <davidgow@google.com>,
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	=?UTF-8?q?G=C3=BCnther=20Noack?= <gnoack@google.com>,
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	Ronald Warsow <rwarsow@gmx.de>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Will Drewry <wad@chromium.org>,
	kernel test robot <oliver.sang@intel.com>,
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	stable@vger.kernel.org
Subject: [PATCH v7 02/10] selftests/landlock: Fix FS tests when run on a private mount point
Date: Sat, 11 May 2024 19:14:37 +0200
Message-ID: <20240511171445.904356-3-mic@digikod.net>
In-Reply-To: <20240511171445.904356-1-mic@digikod.net>
References: <20240511171445.904356-1-mic@digikod.net>
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According to the test environment, the mount point of the test's working
directory may be shared or not, which changes the visibility of the
nested "tmp" mount point for the test's parent process calling
umount("tmp").

This was spotted while running tests in containers [1], where mount
points are private.

Cc: Günther Noack <gnoack@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Link: https://github.com/landlock-lsm/landlock-test-tools/pull/4 [1]
Fixes: 41cca0542d7c ("selftests/harness: Fix TEST_F()'s vfork handling")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20240511171445.904356-3-mic@digikod.net
---

Changes since v1:
* Update commit description.
---
 tools/testing/selftests/landlock/fs_test.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 9a6036fbf289..46b9effd53e4 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -293,7 +293,15 @@ static void prepare_layout(struct __test_metadata *const _metadata)
 static void cleanup_layout(struct __test_metadata *const _metadata)
 {
 	set_cap(_metadata, CAP_SYS_ADMIN);
-	EXPECT_EQ(0, umount(TMP_DIR));
+	if (umount(TMP_DIR)) {
+		/*
+		 * According to the test environment, the mount point of the
+		 * current directory may be shared or not, which changes the
+		 * visibility of the nested TMP_DIR mount point for the test's
+		 * parent process doing this cleanup.
+		 */
+		ASSERT_EQ(EINVAL, errno);
+	}
 	clear_cap(_metadata, CAP_SYS_ADMIN);
 	EXPECT_EQ(0, remove_path(TMP_DIR));
 }
-- 
2.45.0