| Message ID | 20241122143353.59367-19-mic@digikod.net (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | Landlock audit support | expand |
On Nov 22, 2024 =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net> wrote: > > Add audit support for unix_stream_connect, unix_may_send, task_kill, and > file_send_sigiotask hooks. > > Audit event sample: > > type=LL_DENY [...]: domain=195ba459b blockers=scope_abstract_unix_socket path=00666F6F Similar to 17/23, I believe the SOCKADDR record should already capture the socket address information. It would also be nice to see an example record on a signal event. > Cc: Günther Noack <gnoack@google.com> > Cc: Tahera Fahimi <fahimitahera@gmail.com> > Signed-off-by: Mickaël Salaün <mic@digikod.net> > Link: https://lore.kernel.org/r/20241122143353.59367-19-mic@digikod.net > --- > Changes since v1: > - New patch. > --- > security/landlock/audit.c | 8 ++++++ > security/landlock/audit.h | 2 ++ > security/landlock/task.c | 58 ++++++++++++++++++++++++++++++++++++--- > 3 files changed, 64 insertions(+), 4 deletions(-) -- paul-moore.com
On Sat, Jan 04, 2025 at 08:23:53PM -0500, Paul Moore wrote: > On Nov 22, 2024 =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net> wrote: > > > > Add audit support for unix_stream_connect, unix_may_send, task_kill, and > > file_send_sigiotask hooks. > > > > Audit event sample: > > > > type=LL_DENY [...]: domain=195ba459b blockers=scope_abstract_unix_socket path=00666F6F > > Similar to 17/23, I believe the SOCKADDR record should already capture > the socket address information. This might not be the case, which is why SELinux and others explicitly log it I guess. > > It would also be nice to see an example record on a signal event. Yes, I'll add such example. > > > Cc: Günther Noack <gnoack@google.com> > > Cc: Tahera Fahimi <fahimitahera@gmail.com> > > Signed-off-by: Mickaël Salaün <mic@digikod.net> > > Link: https://lore.kernel.org/r/20241122143353.59367-19-mic@digikod.net > > --- > > Changes since v1: > > - New patch. > > --- > > security/landlock/audit.c | 8 ++++++ > > security/landlock/audit.h | 2 ++ > > security/landlock/task.c | 58 ++++++++++++++++++++++++++++++++++++--- > > 3 files changed, 64 insertions(+), 4 deletions(-) > > -- > paul-moore.com
On Mon, Jan 6, 2025 at 9:51 AM Mickaël Salaün <mic@digikod.net> wrote: > On Sat, Jan 04, 2025 at 08:23:53PM -0500, Paul Moore wrote: > > On Nov 22, 2024 =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net> wrote: > > > > > > Add audit support for unix_stream_connect, unix_may_send, task_kill, and > > > file_send_sigiotask hooks. > > > > > > Audit event sample: > > > > > > type=LL_DENY [...]: domain=195ba459b blockers=scope_abstract_unix_socket path=00666F6F > > > > Similar to 17/23, I believe the SOCKADDR record should already capture > > the socket address information. > > This might not be the case, which is why SELinux and others explicitly > log it I guess. I think I may be misunderstanding you, can you point to the section of SELinux code that you are referring to in your comment?
On Mon, Jan 06, 2025 at 05:33:07PM -0500, Paul Moore wrote: > On Mon, Jan 6, 2025 at 9:51 AM Mickaël Salaün <mic@digikod.net> wrote: > > On Sat, Jan 04, 2025 at 08:23:53PM -0500, Paul Moore wrote: > > > On Nov 22, 2024 =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net> wrote: > > > > > > > > Add audit support for unix_stream_connect, unix_may_send, task_kill, and > > > > file_send_sigiotask hooks. > > > > > > > > Audit event sample: > > > > > > > > type=LL_DENY [...]: domain=195ba459b blockers=scope_abstract_unix_socket path=00666F6F > > > > > > Similar to 17/23, I believe the SOCKADDR record should already capture > > > the socket address information. > > > > This might not be the case, which is why SELinux and others explicitly > > log it I guess. > > I think I may be misunderstanding you, can you point to the section of > SELinux code that you are referring to in your comment? I'm refering to struct lsm_network_audit, and the related information ending in the logs with LSM_AUDIT_DATA_NET. Landlock follows the current implementations, hence the generalization brought by the second patch with audit_log_lsm_data().
diff --git a/security/landlock/audit.c b/security/landlock/audit.c index 0b69b4c9ba1c..7e4acc746cd6 100644 --- a/security/landlock/audit.c +++ b/security/landlock/audit.c @@ -71,6 +71,14 @@ get_blocker(const enum landlock_request_type type, if (WARN_ON_ONCE(access_bit >= ARRAY_SIZE(net_access_strings))) return "unknown"; return net_access_strings[access_bit]; + + case LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET: + WARN_ON_ONCE(access_bit != -1); + return "scope_abstract_unix_socket"; + + case LANDLOCK_REQUEST_SCOPE_SIGNAL: + WARN_ON_ONCE(access_bit != -1); + return "scope_signal"; } WARN_ON_ONCE(1); diff --git a/security/landlock/audit.h b/security/landlock/audit.h index 1075b0c8401f..1e0a9164bacc 100644 --- a/security/landlock/audit.h +++ b/security/landlock/audit.h @@ -19,6 +19,8 @@ enum landlock_request_type { LANDLOCK_REQUEST_FS_CHANGE_LAYOUT, LANDLOCK_REQUEST_FS_ACCESS, LANDLOCK_REQUEST_NET_ACCESS, + LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET, + LANDLOCK_REQUEST_SCOPE_SIGNAL, }; /* diff --git a/security/landlock/task.c b/security/landlock/task.c index 1decd6f114e8..bdf7adc14e32 100644 --- a/security/landlock/task.c +++ b/security/landlock/task.c @@ -263,13 +263,27 @@ static int hook_unix_stream_connect(struct sock *const sock, const struct landlock_ruleset *const dom = landlock_get_applicable_domain(landlock_get_current_domain(), unix_scope); + struct lsm_network_audit audit_net = { + .sk = other, + }; + struct landlock_request request = { + .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET, + .audit = { + .type = LSM_AUDIT_DATA_NET, + .u.net = &audit_net, + }, + }; /* Quick return for non-landlocked tasks. */ if (!dom) return 0; - if (is_abstract_socket(other) && sock_is_scoped(other, dom)) + if (is_abstract_socket(other) && sock_is_scoped(other, dom)) { + request.layer_plus_one = + landlock_match_layer_level(dom, unix_scope) + 1; + landlock_log_denial(dom, &request); return -EPERM; + } return 0; } @@ -280,6 +294,16 @@ static int hook_unix_may_send(struct socket *const sock, const struct landlock_ruleset *const dom = landlock_get_applicable_domain(landlock_get_current_domain(), unix_scope); + struct lsm_network_audit audit_net = { + .sk = other->sk, + }; + struct landlock_request request = { + .type = LANDLOCK_REQUEST_SCOPE_ABSTRACT_UNIX_SOCKET, + .audit = { + .type = LSM_AUDIT_DATA_NET, + .u.net = &audit_net, + }, + }; if (!dom) return 0; @@ -291,8 +315,12 @@ static int hook_unix_may_send(struct socket *const sock, if (unix_peer(sock->sk) == other->sk) return 0; - if (is_abstract_socket(other->sk) && sock_is_scoped(other->sk, dom)) + if (is_abstract_socket(other->sk) && sock_is_scoped(other->sk, dom)) { + request.layer_plus_one = + landlock_match_layer_level(dom, unix_scope) + 1; + landlock_log_denial(dom, &request); return -EPERM; + } return 0; } @@ -307,6 +335,13 @@ static int hook_task_kill(struct task_struct *const p, { bool is_scoped; const struct landlock_ruleset *dom; + struct landlock_request request = { + .type = LANDLOCK_REQUEST_SCOPE_SIGNAL, + .audit = { + .type = LSM_AUDIT_DATA_TASK, + .u.tsk = p, + }, + }; if (cred) { /* Dealing with USB IO. */ @@ -324,8 +359,12 @@ static int hook_task_kill(struct task_struct *const p, is_scoped = domain_is_scoped(dom, landlock_get_task_domain(p), LANDLOCK_SCOPE_SIGNAL); rcu_read_unlock(); - if (is_scoped) + if (is_scoped) { + request.layer_plus_one = + landlock_match_layer_level(dom, signal_scope) + 1; + landlock_log_denial(dom, &request); return -EPERM; + } return 0; } @@ -334,6 +373,13 @@ static int hook_file_send_sigiotask(struct task_struct *tsk, struct fown_struct *fown, int signum) { const struct landlock_ruleset *dom; + struct landlock_request request = { + .type = LANDLOCK_REQUEST_SCOPE_SIGNAL, + .audit = { + .type = LSM_AUDIT_DATA_TASK, + .u.tsk = tsk, + }, + }; bool is_scoped = false; /* Lock already held by send_sigio() and send_sigurg(). */ @@ -349,8 +395,12 @@ static int hook_file_send_sigiotask(struct task_struct *tsk, is_scoped = domain_is_scoped(dom, landlock_get_task_domain(tsk), LANDLOCK_SCOPE_SIGNAL); rcu_read_unlock(); - if (is_scoped) + if (is_scoped) { + request.layer_plus_one = + landlock_match_layer_level(dom, signal_scope) + 1; + landlock_log_denial(dom, &request); return -EPERM; + } return 0; }
Add audit support for unix_stream_connect, unix_may_send, task_kill, and file_send_sigiotask hooks. Audit event sample: type=LL_DENY [...]: domain=195ba459b blockers=scope_abstract_unix_socket path=00666F6F Cc: Günther Noack <gnoack@google.com> Cc: Tahera Fahimi <fahimitahera@gmail.com> Signed-off-by: Mickaël Salaün <mic@digikod.net> Link: https://lore.kernel.org/r/20241122143353.59367-19-mic@digikod.net --- Changes since v1: - New patch. --- security/landlock/audit.c | 8 ++++++ security/landlock/audit.h | 2 ++ security/landlock/task.c | 58 ++++++++++++++++++++++++++++++++++++--- 3 files changed, 64 insertions(+), 4 deletions(-)