From patchwork Sat Mar 8 18:44:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 14007682 X-Patchwork-Delegate: paul@paul-moore.com Received: from smtp-190b.mail.infomaniak.ch (smtp-190b.mail.infomaniak.ch [185.125.25.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51745215171 for ; Sat, 8 Mar 2025 18:45:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.125.25.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741459504; cv=none; b=E/v/mqNDVGgFPMrZXsFD/IgHsnMmHXVhlOqJmP54U6IifZncLwxs7wUaK8RzeGReXvb1i0wBerhsdNrvfh3XBgPCotb6ggrOH86f4yY1TRdrijsw+KO1ws0z+k67H+xSKKVm3va38uK34UW3CyeOX3MQFdwChL2fA2kRwfJVNXs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741459504; c=relaxed/simple; bh=Wx/6Hx+WDmJ7YB3tMN0nMjUM1VSJv9z1mb1C6KdOc2Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PH6otuMaxu87CyLCSZ2Q+HN5g6aYf9am5uOCPNzVMHgjSjjTuU4zZeGwDcDHrAikbtL/GkLxfPNrM7HYk7kqUAq1zCqmudMvoODVOXg4ZmU6M1zLPpVnFa4uw68ne6q2ND905jM8g25t5UyNoIgTU4hX1QZH4WmyLLWJ4yqfFMU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net; spf=pass smtp.mailfrom=digikod.net; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b=x207Suc9; arc=none smtp.client-ip=185.125.25.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=digikod.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=digikod.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b="x207Suc9" Received: from smtp-4-0000.mail.infomaniak.ch (unknown [IPv6:2001:1600:7:10:40ca:feff:fe05:0]) by smtp-4-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4Z9Bsf1Nw3zS6s; Sat, 8 Mar 2025 19:44:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digikod.net; s=20191114; t=1741459494; bh=IYGEJlWXKfihUib9yAQfNAkO9iNl2ovlfA2BSTm6VT8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x207Suc9QJufPETUpNZ1Bec+NEpYpsrzJFqecAycdkCakiDOX2dsQLZ+TNKOnk5fE iHAhjsNvL0G7VcjpDU6vKiFIBWqeImFfYkystPRHHh8Pkjz8nsCnu0waz7RPLOrM3E 1IdFp2YFkD3G9zWXwhvXco7evM57rGr/aPp76e00= Received: from unknown by smtp-4-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4Z9Bsd2H7hzHcY; Sat, 8 Mar 2025 19:44:53 +0100 (CET) From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: Eric Paris , Paul Moore , =?utf-8?q?G=C3=BCnther_Noack?= , "Serge E . Hallyn" Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Ben Scarlato , Casey Schaufler , Charles Zaffery , Daniel Burgener , Francis Laniel , James Morris , Jann Horn , Jeff Xu , Jorge Lucangeli Obes , Kees Cook , Konstantin Meskhidze , Matt Bobrowski , Mikhail Ivanov , Phil Sutter , Praveen K Paladugu , Robert Salvet , Shervin Oloumi , Song Liu , Tahera Fahimi , Tingmao Wang , Tyler Hicks , audit@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: [PATCH v6 14/26] landlock: Log TCP bind and connect denials Date: Sat, 8 Mar 2025 19:44:10 +0100 Message-ID: <20250308184422.2159360-15-mic@digikod.net> In-Reply-To: <20250308184422.2159360-1-mic@digikod.net> References: <20250308184422.2159360-1-mic@digikod.net> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Infomaniak-Routing: alpha Add audit support to socket_bind and socket_connect hooks. The related blockers are: - net.bind_tcp - net.connect_tcp Audit event sample: type=LANDLOCK_DENY msg=audit(1729738800.349:44): domain=195ba459b blockers=net.connect_tcp daddr=127.0.0.1 dest=80 Cc: Günther Noack Cc: Konstantin Meskhidze Cc: Mikhail Ivanov Signed-off-by: Mickaël Salaün Link: https://lore.kernel.org/r/20250308184422.2159360-15-mic@digikod.net --- Changes since v5: - Move request declaration in the landlock_log_denial() call to not impact allowed requests with audit. Changes since v4: - Rebase on top of the landlock_log_denial() and subject type changes. Changes since v3: - Rename blockers from net_* to net.* Changes since v2: - Remove potentially superfluous IPv6 saddr log, spotted by Francis Laniel. - Cosmetic improvements. --- security/landlock/audit.c | 12 +++++++++ security/landlock/audit.h | 1 + security/landlock/net.c | 51 ++++++++++++++++++++++++++++++++++++--- 3 files changed, 60 insertions(+), 4 deletions(-) diff --git a/security/landlock/audit.c b/security/landlock/audit.c index edb9fbafbcad..6c34758b9ff2 100644 --- a/security/landlock/audit.c +++ b/security/landlock/audit.c @@ -42,6 +42,13 @@ static const char *const fs_access_strings[] = { static_assert(ARRAY_SIZE(fs_access_strings) == LANDLOCK_NUM_ACCESS_FS); +static const char *const net_access_strings[] = { + [BIT_INDEX(LANDLOCK_ACCESS_NET_BIND_TCP)] = "net.bind_tcp", + [BIT_INDEX(LANDLOCK_ACCESS_NET_CONNECT_TCP)] = "net.connect_tcp", +}; + +static_assert(ARRAY_SIZE(net_access_strings) == LANDLOCK_NUM_ACCESS_NET); + static __attribute_const__ const char * get_blocker(const enum landlock_request_type type, const unsigned long access_bit) @@ -59,6 +66,11 @@ get_blocker(const enum landlock_request_type type, if (WARN_ON_ONCE(access_bit >= ARRAY_SIZE(fs_access_strings))) return "unknown"; return fs_access_strings[access_bit]; + + case LANDLOCK_REQUEST_NET_ACCESS: + if (WARN_ON_ONCE(access_bit >= ARRAY_SIZE(net_access_strings))) + return "unknown"; + return net_access_strings[access_bit]; } WARN_ON_ONCE(1); diff --git a/security/landlock/audit.h b/security/landlock/audit.h index 6765a419001d..eeff2c5bfa4f 100644 --- a/security/landlock/audit.h +++ b/security/landlock/audit.h @@ -19,6 +19,7 @@ enum landlock_request_type { LANDLOCK_REQUEST_PTRACE = 1, LANDLOCK_REQUEST_FS_CHANGE_LAYOUT, LANDLOCK_REQUEST_FS_ACCESS, + LANDLOCK_REQUEST_NET_ACCESS, }; /* diff --git a/security/landlock/net.c b/security/landlock/net.c index 6fb3e60bc5ff..f4478e6a2c0b 100644 --- a/security/landlock/net.c +++ b/security/landlock/net.c @@ -7,10 +7,12 @@ */ #include +#include #include #include #include +#include "audit.h" #include "common.h" #include "cred.h" #include "limits.h" @@ -55,6 +57,7 @@ static int current_check_access_socket(struct socket *const sock, }; const struct landlock_cred_security *const subject = landlock_get_applicable_subject(current_cred(), masks, NULL); + struct lsm_network_audit audit_net = {}; if (!subject) return 0; @@ -68,18 +71,48 @@ static int current_check_access_socket(struct socket *const sock, switch (address->sa_family) { case AF_UNSPEC: - case AF_INET: + case AF_INET: { + const struct sockaddr_in *addr4; + if (addrlen < sizeof(struct sockaddr_in)) return -EINVAL; - port = ((struct sockaddr_in *)address)->sin_port; + + addr4 = (struct sockaddr_in *)address; + port = addr4->sin_port; + + if (access_request == LANDLOCK_ACCESS_NET_CONNECT_TCP) { + audit_net.dport = port; + audit_net.v4info.daddr = addr4->sin_addr.s_addr; + } else if (access_request == LANDLOCK_ACCESS_NET_BIND_TCP) { + audit_net.sport = port; + audit_net.v4info.saddr = addr4->sin_addr.s_addr; + } else { + WARN_ON_ONCE(1); + } break; + } #if IS_ENABLED(CONFIG_IPV6) - case AF_INET6: + case AF_INET6: { + const struct sockaddr_in6 *addr6; + if (addrlen < SIN6_LEN_RFC2133) return -EINVAL; - port = ((struct sockaddr_in6 *)address)->sin6_port; + + addr6 = (struct sockaddr_in6 *)address; + port = addr6->sin6_port; + + if (access_request == LANDLOCK_ACCESS_NET_CONNECT_TCP) { + audit_net.dport = port; + audit_net.v6info.daddr = addr6->sin6_addr; + } else if (access_request == LANDLOCK_ACCESS_NET_BIND_TCP) { + audit_net.sport = port; + audit_net.v6info.saddr = addr6->sin6_addr; + } else { + WARN_ON_ONCE(1); + } break; + } #endif /* IS_ENABLED(CONFIG_IPV6) */ default: @@ -149,6 +182,16 @@ static int current_check_access_socket(struct socket *const sock, ARRAY_SIZE(layer_masks))) return 0; + audit_net.family = address->sa_family; + landlock_log_denial(subject, + &(struct landlock_request){ + .type = LANDLOCK_REQUEST_NET_ACCESS, + .audit.type = LSM_AUDIT_DATA_NET, + .audit.u.net = &audit_net, + .access = access_request, + .layer_masks = &layer_masks, + .layer_masks_size = ARRAY_SIZE(layer_masks), + }); return -EACCES; }