From patchwork Fri Mar 15 11:37:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Christian_G=C3=B6ttsche?= X-Patchwork-Id: 13593330 Received: from mail-ed1-f41.google.com (mail-ed1-f41.google.com [209.85.208.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4332A1B7E1; Fri, 15 Mar 2024 11:38:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.41 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710502741; cv=none; b=pjOuI7u4gVZifmoaTNV0oK/mWk8iquHe/ySDvFcP14hOi2dbl3t2NPyVacW6sBnEyRIv1zXCCxoCip2+pWQyZuxt2yiSyfKSvyQz5yoURBX/lduNmfJ7pXPWq5MN7+9m58XNdy75Z62/L/RWfXlDQklIAi3Gh11P8/B6BnUYDSQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710502741; c=relaxed/simple; bh=YhK/jnk1sN0Eu2k73vdEasVnkAA21VPShol4SbhmQDE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=AigQL+p0k9xR64d7kScCl9sY/XShtfoyniyE0HcHQNI4ap1dvUMmQG2lH6PL4MI3h3r4TP4tepeWkHdyLFKkgO0XSFGnhr5NGX1EGZ7AH63bpUrUD8J/TvHLqfQeX0Muye8zOC9/tccoaOzG4EPgPviJqUUWDUcXKdCry4ONHR8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=googlemail.com; spf=pass smtp.mailfrom=googlemail.com; dkim=pass (2048-bit key) header.d=googlemail.com header.i=@googlemail.com header.b=KUfLwR3Y; arc=none smtp.client-ip=209.85.208.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=googlemail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=googlemail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=googlemail.com header.i=@googlemail.com header.b="KUfLwR3Y" Received: by mail-ed1-f41.google.com with SMTP id 4fb4d7f45d1cf-568a3292916so1984175a12.1; Fri, 15 Mar 2024 04:38:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20230601; t=1710502738; x=1711107538; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Ret+NQ/Tw5LK56vjyJDNxqW8M+4jtEPqZMI9umR9cCI=; b=KUfLwR3YydJAheGuADHmPCFzOmeuutYh+cPx3pAcCH1JXoYknT4HVT9fGpGQHhLJDi olBOT21+QWtaOksGCZZ8CHd6EMVD8QEJg4918AHNhf2I62E5flo7lL4zqJRsMDU7tSkI /KjLHhFQ3LP3wzTAq9iTpNJKHaTZeFHWPLaYFzQS6+mtrg4S3DEG2suKfDmG7En7mxhc Yll27I7dKJujo45T8mZwgFHw8iEAhJm92aNa3iQzb/IFiwXvwqqCsR/8Pw6SplacDztV N+9d6NozKyapLVifsnOheV49lTQZGZjObh9/llKi/FIhSOFBYJdC+nf5erbPQW8rhuao V40Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710502738; x=1711107538; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Ret+NQ/Tw5LK56vjyJDNxqW8M+4jtEPqZMI9umR9cCI=; b=er0RKIzF0IcU+kWC90ZhsiiCBSbhUkp2gA5VaqtcF2On1rKBtbSs1mQqtkmD0zvV1Y cqxNAKCjrWRra/Zo1WagShjBECx7tJsGMbm8s0e+iJkhu+AJug6VbHmLMF9iyirBqIjr ueeon/g/EYndS3y1pM5Efjjw0eAvybhA23DNVaaVrLDjSrT1PWVvxUZRL3pD0TA5vH5M PNSjCrjt69l2mMZBqcEOVpLgFlAkoTp6YSkYnWj49PGME05TccHUqiuI8obX0/LqDfcV 9z/ZcA/jd03Mmq637BbxTxK0p9koyNzLR705XgJ+QbgocOaoa9/PF0hUMev6jNXvpfUg y7EQ== X-Forwarded-Encrypted: i=1; AJvYcCWTWCZDE67T9IvmI0YS4CbbuhFeKCMu6uUu1Zg9qo+Z8onEHrZknnbxYsBA+Pbs5O3h2UVy5ZIAdhCyc+QqDYjPvsp77hQ4qYAIU6kb91XS6xVeH9MzljrD0ODBA8UsYfRULFOKuFhVXwyX1n4+qDo8H0DqxqozFaUC1A== X-Gm-Message-State: AOJu0Ywzp54EqvzcF+2uV6FJxeco5CfEWjSddoxAOHAJXAk1QRjZ7rAs ZQshyNSg7RA1BJS464uoBN4fZqaPA7dXXo75oGC8IzDJQUKBAWDAKKSqAO/B++3GPQ== X-Google-Smtp-Source: AGHT+IHxB7FB377TOoio0unYbfIwnkxt4g5n3Z4MDqCqa7L7No5w/MvY3FrF55UMKEirChoiUMRGJg== X-Received: by 2002:a05:6402:530a:b0:568:797a:f2d with SMTP id eo10-20020a056402530a00b00568797a0f2dmr2968341edb.27.1710502737191; Fri, 15 Mar 2024 04:38:57 -0700 (PDT) Received: from ddev.DebianHome (dynamic-095-119-217-226.95.119.pool.telefonica.de. [95.119.217.226]) by smtp.gmail.com with ESMTPSA id fg3-20020a056402548300b005682f47aea7sm1610024edb.94.2024.03.15.04.38.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 Mar 2024 04:38:56 -0700 (PDT) From: =?utf-8?q?Christian_G=C3=B6ttsche?= To: linux-security-module@vger.kernel.org Cc: linux-block@vger.kernel.org, Paul Moore , John Johansen , James Morris , "Serge E. Hallyn" , Stephen Smalley , Ondrej Mosnacek , Casey Schaufler , Christian Brauner , Roberto Sassu , Mimi Zohar , Khadija Kamran , Andrii Nakryiko , linux-kernel@vger.kernel.org, apparmor@lists.ubuntu.com, selinux@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH 01/10] capability: introduce new capable flag CAP_OPT_NOAUDIT_ONDENY Date: Fri, 15 Mar 2024 12:37:22 +0100 Message-ID: <20240315113828.258005-1-cgzones@googlemail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Introduce a new capable flag, CAP_OPT_NOAUDIT_ONDENY, to not generate an audit event if the requested capability is not granted. This will be used in a new capable_any() functionality to reduce the number of necessary capable calls. Handle the flag accordingly in AppArmor and SELinux. CC: linux-block@vger.kernel.org Suggested-by: Paul Moore Signed-off-by: Christian Göttsche Reviewed-by: Serge Hallyn Acked-by: Paul Moore Acked-by: John Johansen --- v5: rename flag to CAP_OPT_NOAUDIT_ONDENY, suggested by Serge: https://lore.kernel.org/all/20230606190013.GA640488@mail.hallyn.com/ --- include/linux/security.h | 2 ++ security/apparmor/capability.c | 8 +++++--- security/selinux/hooks.c | 14 ++++++++------ 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/include/linux/security.h b/include/linux/security.h index 41a8f667bdfa..c60cae78ff8b 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -70,6 +70,8 @@ struct lsm_ctx; #define CAP_OPT_NOAUDIT BIT(1) /* If capable is being called by a setid function */ #define CAP_OPT_INSETID BIT(2) +/* If capable should audit the security request for authorized requests only */ +#define CAP_OPT_NOAUDIT_ONDENY BIT(3) /* LSM Agnostic defines for security_sb_set_mnt_opts() flags */ #define SECURITY_LSM_NATIVE_LABELS 1 diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c index 9934df16c843..08c9c9a0fc19 100644 --- a/security/apparmor/capability.c +++ b/security/apparmor/capability.c @@ -108,7 +108,8 @@ static int audit_caps(struct apparmor_audit_data *ad, struct aa_profile *profile * profile_capable - test if profile allows use of capability @cap * @profile: profile being enforced (NOT NULL, NOT unconfined) * @cap: capability to test if allowed - * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated + * @opts: CAP_OPT_NOAUDIT/CAP_OPT_NOAUDIT_ONDENY bit determines whether audit + * record is generated * @ad: audit data (MAY BE NULL indicating no auditing) * * Returns: 0 if allowed else -EPERM @@ -126,7 +127,7 @@ static int profile_capable(struct aa_profile *profile, int cap, else error = -EPERM; - if (opts & CAP_OPT_NOAUDIT) { + if ((opts & CAP_OPT_NOAUDIT) || ((opts & CAP_OPT_NOAUDIT_ONDENY) && error)) { if (!COMPLAIN_MODE(profile)) return error; /* audit the cap request in complain mode but note that it @@ -143,7 +144,8 @@ static int profile_capable(struct aa_profile *profile, int cap, * @subj_cred: cred we are testing capability against * @label: label being tested for capability (NOT NULL) * @cap: capability to be tested - * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated + * @opts: CAP_OPT_NOAUDIT/CAP_OPT_NOAUDIT_ONDENY bit determines whether audit + * record is generated * * Look up capability in profile capability set. * diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 3448454c82d0..1a2c7c1a89be 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1624,7 +1624,7 @@ static int cred_has_capability(const struct cred *cred, u16 sclass; u32 sid = cred_sid(cred); u32 av = CAP_TO_MASK(cap); - int rc; + int rc, rc2; ad.type = LSM_AUDIT_DATA_CAP; ad.u.cap = cap; @@ -1643,11 +1643,13 @@ static int cred_has_capability(const struct cred *cred, } rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); - if (!(opts & CAP_OPT_NOAUDIT)) { - int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad); - if (rc2) - return rc2; - } + if ((opts & CAP_OPT_NOAUDIT) || ((opts & CAP_OPT_NOAUDIT_ONDENY) && rc)) + return rc; + + rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad); + if (rc2) + return rc2; + return rc; }