From 03197e40a22c2641a1f9d1744418cd29f4954b83 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Sat, 9 Nov 2024 12:08:56 +0100 Subject: [PATCH] landlock: Optimize scope enforcement MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Do not walk through the domain hierarchy when the required scope is not supported by this domain. This is the same approach as for filesystem and network restrictions. Cc: Mikhail Ivanov Cc: Tahera Fahimi Reviewed-by: Günther Noack Link: https://lore.kernel.org/r/20241109110856.222842-4-mic@digikod.net Signed-off-by: Mickaël Salaün --- security/landlock/task.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/security/landlock/task.c b/security/landlock/task.c index 4acbd7c40eee..dc7dab78392e 100644 --- a/security/landlock/task.c +++ b/security/landlock/task.c @@ -204,12 +204,17 @@ static bool is_abstract_socket(struct sock *const sock) return false; } +static const struct access_masks unix_scope = { + .scope = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET, +}; + static int hook_unix_stream_connect(struct sock *const sock, struct sock *const other, struct sock *const newsk) { const struct landlock_ruleset *const dom = - landlock_get_current_domain(); + landlock_get_applicable_domain(landlock_get_current_domain(), + unix_scope); /* Quick return for non-landlocked tasks. */ if (!dom) @@ -225,7 +230,8 @@ static int hook_unix_may_send(struct socket *const sock, struct socket *const other) { const struct landlock_ruleset *const dom = - landlock_get_current_domain(); + landlock_get_applicable_domain(landlock_get_current_domain(), + unix_scope); if (!dom) return 0; @@ -243,6 +249,10 @@ static int hook_unix_may_send(struct socket *const sock, return 0; } +static const struct access_masks signal_scope = { + .scope = LANDLOCK_SCOPE_SIGNAL, +}; + static int hook_task_kill(struct task_struct *const p, struct kernel_siginfo *const info, const int sig, const struct cred *const cred) @@ -256,6 +266,7 @@ static int hook_task_kill(struct task_struct *const p, } else { dom = landlock_get_current_domain(); } + dom = landlock_get_applicable_domain(dom, signal_scope); /* Quick return for non-landlocked tasks. */ if (!dom) @@ -279,7 +290,8 @@ static int hook_file_send_sigiotask(struct task_struct *tsk, /* Lock already held by send_sigio() and send_sigurg(). */ lockdep_assert_held(&fown->lock); - dom = landlock_file(fown->file)->fown_domain; + dom = landlock_get_applicable_domain( + landlock_file(fown->file)->fown_domain, signal_scope); /* Quick return for unowned socket. */ if (!dom)