[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <614b4c36-e0a1-1fc2-cec3-017a7d2bcebb@huawei-partners.com>
Date: Thu, 19 Sep 2024 13:53:54 +0300
From: Mikhail Ivanov <ivanov.mikhail1@...wei-partners.com>
To: Günther Noack <gnoack@...gle.com>
CC: <mic@...ikod.net>, <willemdebruijn.kernel@...il.com>,
<gnoack3000@...il.com>, <linux-security-module@...r.kernel.org>,
<netdev@...r.kernel.org>, <netfilter-devel@...r.kernel.org>,
<yusongping@...wei.com>, <artem.kuzin@...wei.com>,
<konstantin.meskhidze@...wei.com>
Subject: Re: [RFC PATCH v3 12/19] selftests/landlock: Test that kernel space
sockets are not restricted
On 9/18/2024 4:00 PM, Günther Noack wrote:
> This is a good way to test this, IMHO. Good find.
> The comment at the bottom is really valuable. :)
>
> Out of curiosity: I suspect that a selftest with NFS or another network-backed
> filesystem might be too complicated? Have you tried that manually, by any
> chance?
I haven't, just ran through a code a little bit. I think that testing
NFS is possible, but it depends on which scenario we want to test.
Simple creation of a server may require only to mount NFS with the
appropriate parameters. Anyway, I don't see any reason for implementing
such test if restriction of kernel sockets is already tested with SMC
socket creation.
>
>
> On Wed, Sep 04, 2024 at 06:48:17PM +0800, Mikhail Ivanov wrote:
>> Add test validating that Landlock provides restriction of user space
>> sockets only.
>>
>> Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@...wei-partners.com>
>> ---
>> .../testing/selftests/landlock/socket_test.c | 39 ++++++++++++++++++-
>> 1 file changed, 38 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/landlock/socket_test.c b/tools/testing/selftests/landlock/socket_test.c
>> index ff5ace711697..23698b8c2f4d 100644
>> --- a/tools/testing/selftests/landlock/socket_test.c
>> +++ b/tools/testing/selftests/landlock/socket_test.c
>> @@ -7,7 +7,7 @@
>>
>> #define _GNU_SOURCE
>>
>> -#include <linux/landlock.h>
>> +#include "landlock.h"
>> #include <linux/pfkeyv2.h>
>> #include <linux/kcm.h>
>> #include <linux/can.h>
>> @@ -628,4 +628,41 @@ TEST(unsupported_af_and_prot)
>> EXPECT_EQ(ESOCKTNOSUPPORT, test_socket(AF_UNIX, SOCK_PACKET, 0));
>> }
>>
>> +TEST(kernel_socket)
>> +{
>> + const struct landlock_ruleset_attr ruleset_attr = {
>> + .handled_access_socket = LANDLOCK_ACCESS_SOCKET_CREATE,
>> + };
>> + struct landlock_socket_attr smc_socket_create = {
>> + .allowed_access = LANDLOCK_ACCESS_SOCKET_CREATE,
>> + .family = AF_SMC,
>> + .type = SOCK_STREAM,
>> + };
>> + int ruleset_fd;
>> +
>> + /*
>> + * Checks that SMC socket is created sucessfuly without
>
> Typo nit: "successfully"
> ^^ ^^
Thanks, will be fixed.
>
>> + * landlock restrictions.
>> + */
>> + ASSERT_EQ(0, test_socket(AF_SMC, SOCK_STREAM, 0));
>> +
>> + ruleset_fd =
>> + landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
>> + ASSERT_LE(0, ruleset_fd);
>> +
>> + ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_SOCKET,
>> + &smc_socket_create, 0));
>> + enforce_ruleset(_metadata, ruleset_fd);
>> + ASSERT_EQ(0, close(ruleset_fd));
>> +
>> + /*
>> + * During the creation of an SMC socket, an internal service TCP socket
>> + * is also created (Cf. smc_create_clcsk).
>> + *
>> + * Checks that Landlock does not restrict creation of the kernel space
>> + * socket.
>> + */
>> + EXPECT_EQ(0, test_socket(AF_SMC, SOCK_STREAM, 0));
>> +}
>> +
>> TEST_HARNESS_MAIN
>> --
>> 2.34.1
>>
>
> Reviewed-by: Günther Noack <gnoack@...gle.com>
Powered by blists - more mailing lists