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Message-ID: <c7320eda-6501-d133-07b3-b516836334be@huawei.com> Date: Mon, 23 Oct 2023 11:56:06 +0300 From: "Konstantin Meskhidze (A)" <konstantin.meskhidze@...wei.com> To: Mickaël Salaün <mic@...ikod.net> CC: <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> Subject: Re: [PATCH v13 08/12] landlock: Add network rules and TCP hooks support 10/23/2023 11:30 AM, Mickaël Salaün пишет: > On Mon, Oct 23, 2023 at 10:23:35AM +0300, Konstantin Meskhidze (A) wrote: >> >> >> 10/20/2023 6:41 PM, Mickaël Salaün пишет: >> > On Fri, Oct 20, 2023 at 02:58:31PM +0300, Konstantin Meskhidze (A) wrote: >> > > >> > > >> > > 10/20/2023 12:49 PM, Mickaël Salaün пишет: >> > > > On Fri, Oct 20, 2023 at 07:08:33AM +0300, Konstantin Meskhidze (A) wrote: >> > > > > > > > > 10/18/2023 3:29 PM, Mickaël Salaün пишет: >> > > > > > On Mon, Oct 16, 2023 at 09:50:26AM +0800, Konstantin Meskhidze wrote: >> > >> > > > > > > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >> > > > > > > index 4c209acee01e..1fe4298ff4a7 100644 >> > > > > > > --- a/security/landlock/ruleset.c >> > > > > > > +++ b/security/landlock/ruleset.c >> > > > > > > @@ -36,6 +36,11 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >> > > > > > > refcount_set(&new_ruleset->usage, 1); >> > > > > > > mutex_init(&new_ruleset->lock); >> > > > > > > new_ruleset->root_inode = RB_ROOT; >> > > > > > > + >> > > > > > > +#if IS_ENABLED(CONFIG_INET) >> > > > > > > + new_ruleset->root_net_port = RB_ROOT; >> > > > > > > +#endif /* IS_ENABLED(CONFIG_INET) */ >> > > > > > > + >> > > > > > > new_ruleset->num_layers = num_layers; >> > > > > > > /* >> > > > > > > * hierarchy = NULL >> > > > > > > @@ -46,16 +51,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >> > > > > > > } >> > > > > > > > > struct landlock_ruleset * >> > > > > > > -landlock_create_ruleset(const access_mask_t fs_access_mask) >> > > > > > > +landlock_create_ruleset(const access_mask_t fs_access_mask, >> > > > > > > + const access_mask_t net_access_mask) >> > > > > > > { >> > > > > > > struct landlock_ruleset *new_ruleset; >> > > > > > > > > /* Informs about useless ruleset. */ >> > > > > > > - if (!fs_access_mask) >> > > > > > > + if (!fs_access_mask && !net_access_mask) >> > > > > > > return ERR_PTR(-ENOMSG); >> > > > > > > new_ruleset = create_ruleset(1); >> > > > > > > - if (!IS_ERR(new_ruleset)) >> > > > > > > + if (IS_ERR(new_ruleset)) >> > > > > > > + return new_ruleset; >> > > > > > > + if (fs_access_mask) >> > > > > > > landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >> > > > > > > + if (net_access_mask) >> > > > > > > + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); >> > > > > > > This is good, but it is not tested: we need to add a test that >> > > > > both >> > > > > > handle FS and net restrictions. You can add one in net.c, just handling >> > > > > > LANDLOCK_ACCESS_FS_READ_DIR and LANDLOCK_ACCESS_NET_BIND_TCP, add one >> > > > > > rule with path_beneath (e.g. /dev) and another with net_port, and check >> > > > > > that open("/") is denied, open("/dev") is allowed, and and only the >> > > > > > allowed port is allowed with bind(). This test should be simple and can >> > > > > > only check against an IPv4 socket, i.e. using ipv4_tcp fixture, just >> > > > > > after port_endianness. fcntl.h should then be included by net.c >> > > > > > > Ok. >> > > > > > > I guess that was the purpose of layout1.with_net (in fs_test.c) >> > > > > but it >> > > > > > > Yep. I added this kind of nest in fs_test.c to test both >> > > fs and network >> > > > > rules together. >> > > > > > is not complete. You can revamp this test and move it to net.c >> > > > > > following the above suggestions, keeping it consistent with other tests >> > > > > > in net.c . You don't need the test_open() nor create_ruleset() helpers. >> > > > > > > This test must failed if we change >> > > > > "ruleset->access_masks[layer_level] |=" >> > > > > > to "ruleset->access_masks[layer_level] =" in >> > > > > > landlock_add_fs_access_mask() or landlock_add_net_access_mask(). >> > > > > > > Do you want to change it? Why? >> > > > > The kernel code is correct and must not be changed. However, if >> > > by >> > > > mistake we change it and remove the OR, a test should catch that. We >> > > > need a test to assert this assumption. >> > > > OK. I will add additional assert simulating >> > > "ruleset->access_masks[layer_level] =" kernel code. >> > > > > Fs and network masks are ORed to not intersect with each other. >> > > > > Yes, they are ORed, and we need a test to check that. Noting is >> > > > currently testing this OR (and the different rule type consistency). >> > > > I'm suggesting to revamp the layout1.with_net test into >> > > > ipv4_tcp.with_fs and make it check ruleset->access_masks[] and rule >> > > > addition of different types. >> > > >> > > I will move layout1.with_net test into net.c and rename it. Looks like >> > > it just needed to add "ruleset->access_masks[layer_level] =" assert >> > > because the test already has rule addition with different types. >> > >> > The with_net test doesn't have FS rules, which is the main missing part. >> > You'll need to rely on the net.c helpers, use the hardcoded paths, and >> > only handle one access right of each type as I suggested above. >> > >> >> This is with_net code: >> >> .... >> /* Adds a network rule. */ >> >> ASSERT_EQ(0, landlock_add_rule(ruleset_fd_net, LANDLOCK_RULE_NET_PORT, >> &tcp_bind, 0)); >> >> enforce_ruleset(_metadata, ruleset_fd_net); >> ASSERT_EQ(0, close(ruleset_fd_net)); >> >> ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules); >> >> ASSERT_LE(0, ruleset_fd); >> enforce_ruleset(_metadata, ruleset_fd); >> ASSERT_EQ(0, close(ruleset_fd)); >> .... >> >> It has FS rules - just after ruleset_fd_net rule inforced. >> Or maybe I missed something? > > ruleset_fd_net and ruleset_fd are two different rulesets, and then > they create two different layers. We need to test support for FS and net > with the same ruleset/layer to check ruleset->access_masks[layer_level]. > Got your point here. Thanks. >> >> > > >> > > Do you have any more review updates so far? >> > >> > That's all for this patch series. :) >> >> Ok. Thanks. >> > . > .
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