From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-relay-internal-1.canonical.com (smtp-relay-internal-1.canonical.com [185.125.188.123]) (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 3E50E28A71C for ; Wed, 7 May 2025 15:37:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.125.188.123 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746632254; cv=none; b=aBx/iu+mGfcX7Nka2OzH7UayCrHCKRfZlMd1EbM9kCIIp1LK0L89+IJvD1CSOsgWgkpCQ6nYbccwUSjuBRFOdhVnQpBz0E5NykZW8Xxl8UEG/kVbYWHvgUZ3CVeIW8PVI3iOHn8G6Z3cdiWB/OU5qhMncQk9gKxHHIgLFT3Hcow= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746632254; c=relaxed/simple; bh=itefw7osb12hSN2O1c0KuZaS6PgNbKAO+Y/ON68WOpQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mhwPot7IqzR3SPb49vMdWCcR9hdwAx4fISxoTAvzcU0FB7VpvXYyQoPSvtMmUFHd/gQkwDX1/LvBX1tb4j8PT1TtTR2U0NnEs6ExRlrIl2yfUJJ/QGCaE+pD8aBLaMKfL7AUBqqmHvwgWT4wYJvYo4s5/L5/JZrWJ7yImqADDV0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=canonical.com; spf=pass smtp.mailfrom=canonical.com; dkim=pass (2048-bit key) header.d=canonical.com header.i=@canonical.com header.b=YEEtBq8k; arc=none smtp.client-ip=185.125.188.123 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=canonical.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=canonical.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=canonical.com header.i=@canonical.com header.b="YEEtBq8k" Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-1.canonical.com (Postfix) with ESMTPS id A5AFA3F174 for ; Wed, 7 May 2025 15:37:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1746632249; bh=fr9yeU7dVZUGfHuigq4Ki6OIiok3yQVQgVBSFzRvIM8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YEEtBq8k3pUOamZwPvE0TraNlTMzDuXi+Lgc+QYOHcJbqk2jKPMlR5S81LL153EuR uUyItELMo8a/ybko7mXc5tn6Yts9Gf1EkMdKI+fAH4VSY4NbwWrqOZzuqXoBZdeI2X ULy7fIFnoNR1vYvksGGzrKZwJvzdcz3nqKECxQMqHuPc+yQ7YbvXr113DmYMkQkLPm MFhA807gKdPRA95DD42kXtG9McTUg0ql58VR2mzeebHk8EH5RgsXj5Dq54mdyjgjJA YbYBsdAW38IOA6BzIj7lLEnuPTvX4/M4muHVvbRSGFHISqj9jObHcAoubS3btyD0Es bZ+1k0W3QKqmg== Received: by mail-ej1-f72.google.com with SMTP id a640c23a62f3a-acb67aad0e2so4839566b.0 for ; Wed, 07 May 2025 08:37:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746632247; x=1747237047; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=fr9yeU7dVZUGfHuigq4Ki6OIiok3yQVQgVBSFzRvIM8=; b=KnJAdakWI+fe36z07JyzaM5UTd/s/cS5QbjVyQ4Ur3Wk3WEsLXiC1W8mIIC1PQtIAs NZKj5rBBwSHBURi66BqftUgCzyXdXo5/ms8ZmlBGY4qxA5ap9sTeR0GUMnRFywQX5P7j XqU/WxeyKosqaKwt9H8Qs4lZ0TtmLKyIseJeT0UvFjzZ9hiL+yIkymtDejQrnNbhYt+s +ASGNI1s7aw3R0Em56VavuZwftNMzGAv5igsfB03OhECSfaVNrvlksM5ke8yZx1JBvVa raNLUBod0wx6E45yulDthjP3tyhYiLfi696CkHBrpO9NdABjSrdeTL7VCOKyTItrAIyd a8mQ== X-Forwarded-Encrypted: i=1; AJvYcCXAIAycqfsxzbLQdHtvF3uWpnVwYtTbsN5fA8EuFdpvM4FsThjRxLmxL5jwpcl6lwF3zuUhso90yeU=@vger.kernel.org X-Gm-Message-State: AOJu0YzPB6gfi185OYyIhOIcfDDwQBSYcD2dNCZAlBYmJEcUokgPENHD tQ+1gkgQD0j6khmIjpOj5ztRqsZxnTqtQ9CEwCGFQNz0OcIU6WtMloEsAOIB7pvYF2sIdK8X6v4 /4xDtVQL2LEvGxsOglM3UiGVewtMVmJnq3PSfLohEf2IhsiLgghOTP8llU58XXrl2g56sqvITVg == X-Gm-Gg: ASbGncvrOO99dOaLcM+Jx79jowPOVBC5IhKyd+kiu3jChirKIV0fOgdvGq9jF+bi/dj 1JavgicLILrpXY8MmMvX75YLzVzMo7gWM2QqKgNWRn7JFXzLt8N4BU0mRW2KsPidGO4s60elFMh LkeHdWbgJAcWEuQUcMSI2svMb2GPM4NX0OtnJW9H4UYBbPhVm+mrQCyEY+LtGhqicZSf3LoiOq9 vecO2KdIP+tsqWQk8wCGliGFskAISqt2oAYUe7rDP6SNprC/XwicZ0lwAGYd8m29ORtlo0JDtmG JOTwHEbmsqAbJvi7ZVc4cRDPjMYvfFWotnbTr5R8ijtN24WQg/nw04UyGMYnkYBu6Nc= X-Received: by 2002:a17:907:cd0d:b0:ace:be7c:11df with SMTP id a640c23a62f3a-ad1eaefaedcmr364827466b.6.1746632246821; Wed, 07 May 2025 08:37:26 -0700 (PDT) X-Google-Smtp-Source: AGHT+IE3LQvsicm0YBjAOHirumoX4UDCK+hCXE9ScCJp5xtKINT4FyusXCl/66Pqvnso9XRhvIDAPw== X-Received: by 2002:a17:907:cd0d:b0:ace:be7c:11df with SMTP id a640c23a62f3a-ad1eaefaedcmr364824366b.6.1746632246505; Wed, 07 May 2025 08:37:26 -0700 (PDT) Received: from ?IPV6:2001:861:3280:410:2ef0:5dff:fe60:6274? ([2001:861:3280:410:2ef0:5dff:fe60:6274]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ad1891ef1e0sm923525466b.77.2025.05.07.08.37.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 May 2025 08:37:26 -0700 (PDT) Message-ID: Date: Wed, 7 May 2025 17:37:25 +0200 Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] lsm: introduce security_lsm_manage_policy hook To: Song Liu Cc: linux-security-module@vger.kernel.org, john.johansen@canonical.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, mic@digikod.net, kees@kernel.org, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, takedakn@nttdata.co.jp, penguin-kernel@i-love.sakura.ne.jp, linux-api@vger.kernel.org, apparmor@lists.ubuntu.com, linux-kernel@vger.kernel.org References: <20250506143254.718647-1-maxime.belair@canonical.com> <20250506143254.718647-3-maxime.belair@canonical.com> Content-Language: en-US From: =?UTF-8?Q?Maxime_B=C3=A9lair?= Autocrypt: addr=maxime.belair@canonical.com; keydata= xsDNBGWdWVYBDADTTxrLrewr4UPUa9CvBTsQFOLNM1D8rvhDyf0UWHD0Z3EuqePliDUpQ1FQ EaDAd1qEmsf4ybF8dWN37OC25iBmolZv+tzpRmlhTQtyBu/xWu5LwWIpLFhQq+9AkcHa4Za8 2/ovK84K9u8RPN6Y9h/UOzAS23UI86T58KxzDHEHbRC5XA5VmOgcX71FQDalvMUaAHJV/WRe OifBAwPbapTmTuKEmuLXvDczKqAADKWHXi7JECpY+1Mpd9xRd9dWu7ooKQ+KmOFOZcOxKagY 9+qK77wUzgDleDU8ihuzOWol+K5vZg0saiRJQm8l9mhIXrREloiUntScBraHBSqSy0kMuIK7 bmIflfgDarYVXV5rxotIWu0guyn8kT/N+DKghi52/VbDdOBngwYLTBO3sZtIdw0pkhkwHDcl se+BThNz6xC0UXlSZrUBQ5RBruBSTXZHwZM9Oyhlf+S1EtZe2jO1R2hSZ0rrHJ/93LT5ARFd jGInAz6ocW0He8FB5nGjfQcAEQEAAc0sTWF4aW1lIELDqWxhaXIgPG1heGltZS5iZWxhaXJA Y2Fub25pY2FsLmNvbT7CwQ4EEwEKADgWIQTKdrj/a+71WSW+OmUnvE/6RFk5uAUCZZ1ZVgIb AwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAKCRAnvE/6RFk5uL/BC/98c45dc+GgTCgYO8YY lXJ/N9+QZyw5n4CBcXphBkd/xZkwlOgJ4bY5zHH3ukKBfuNB77RLRT+mzHwnCELXRqQOebtN ZhI2JDvdAwemyxsstj1lSadYhlRDjxLmphARRbiJ9q8g3MMhv/zLcM5ObFfSP4lQaxaiSEjw pAJNLR7d9rsMUYi/lWxQKDcjGaKnQkq5qDtLzoWw6pIf2VKGQDbibPdVTiedByIbF6x21LEQ rVNHTOnqoqC2X6JiSWz4pCuYRQM7bY1BW0ZUOWnshJNQqi8+4/A/h+Yss3vXp82+oKRw7Dls /B5MjR4yHdCBb8RWM0y0kghpvjMmp5Nbsh5XaDu2yv5qkxs4NHoklalUvBy34O2lx0ITVSGN pbzw93cUZtomDRtXder0cY6FPVNrN8aP6PljoYrobVDCb451nc1YrFEiMUG8jCfD85JpwK+S Ql9RccaMFTcPXe0rFWr7ecwjEtxDd6/Mu9tpW1mLMOKF5TJxrmVtbAIauPgKp0rOwM0EZZ1Z VgEMANEV0CsOdJHC9VROvdooRgl8Q7E19QdsCpDD1rziS1KeegSPo5n1uDsXoW88Rdpxqap0 fcgECJxZfH4bgHr0G/pWHbbltfM7jdvdW+cXD/8wVBgzZrbysPa9WpaM/S/DXj2qVIng3O43 izSedJ81iYyvi7i2e4YtZndGsz8DslaUDqBCHKvG5ydp/9W0Wj55SxYCmt1rdv5GUYULoVhI uevY8olct38tl7rSZxBpzez3rK3WCQkSN1uf8zzluDLWXEmJjafJfzO5YC6s+ScZ7kXEIcJC ttGXwVJWJF+Yq7EKaGoEMK+5e4SJgok6vrx3f+lKa3R70jqwAj1ulsvS3LRgrjtN8dhIuJdE aSNTkEO5TvrHzcDk/v5X7Tn7YOo4qheqC4k+PzNBI/Y4TGY6FJFskaii89wRVmSg3meRv9p4 kT2XXtNueH/CWtwvSK3f+2u21DbNnknjSXg0lNlO380NwN1Q0BnDTPcASENd5T4gwxBw5GED H6yK2jn5bFMUxwARAQABwsD2BBgBCgAgFiEEyna4/2vu9VklvjplJ7xP+kRZObgFAmWdWVYC GwwACgkQJ7xP+kRZObiqjQwAlD/IBOVIkpuGjO7LoxpA8qe63AO1HygvGVOlFHLrw4ap+edK bUpmEzht20VQNtzyosBbXYDDrcFiSiTNoBKFYx7ekfQ+OwxzU0wOkUJ2m56EKAlUHotwnHm+ s1FF7SFQO7oubKCZPSjPgex8XmY43uZXnKmsoFC0iJdB6a8wOPIk10VpaEfgrGdwUPeDchAX ZSAEPZRM0C2JDjghdIlVek0goTWh4RARJ/Mz73K0VZoqxecSArSglOqlpUO2YETJGB8kR6Ip uk605mf+aJoQq/8DtoYOTFFaTViKlKgVoNi0e1il6HkEhASyGQeQZkcq92O6ndDm//csiJT2 oRAG5XUu5Q1PWG0oY4cZ6XN1z8nkj5Mj23SRhBwVjh2PY2p4cyFRTBrBDaNV38LHw6tVjdhk 8YNqGOVqceueWdZmWbp8b88a0wzOcrPAvcxJ14FhMyMO9P7FblDYLNYr0oAYj+UyhxOPbRZz yriCIKEAbLqHTyj+RhbroZmv5q3X7iVq In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 5/7/25 08:19, Song Liu wrote: > On Tue, May 6, 2025 at 7:40 AM Maxime Bélair > wrote: >> >> Define a new LSM hook security_lsm_manage_policy and wire it into the >> lsm_manage_policy() syscall so that LSMs can register a unified interface >> for policy management. This initial, minimal implementation only supports >> the LSM_POLICY_LOAD operation to limit changes. >> >> Signed-off-by: Maxime Bélair > [...] >> diff --git a/security/security.c b/security/security.c >> index fb57e8fddd91..256104e338b1 100644 >> --- a/security/security.c >> +++ b/security/security.c >> @@ -5883,6 +5883,27 @@ int security_bdev_setintegrity(struct block_device *bdev, >> } >> EXPORT_SYMBOL(security_bdev_setintegrity); >> >> +/** >> + * security_lsm_manage_policy() - Manage the policies of LSMs >> + * @lsm_id: id of the lsm to target >> + * @op: Operation to perform (one of the LSM_POLICY_XXX values) >> + * @buf: userspace pointer to policy data >> + * @size: size of @buf >> + * @flags: lsm policy management flags >> + * >> + * Manage the policies of a LSM. This notably allows to update them even when >> + * the lsmfs is unavailable is restricted. Currently, only LSM_POLICY_LOAD is >> + * supported. >> + * >> + * Return: Returns 0 on success, error on failure. >> + */ >> +int security_lsm_manage_policy(u32 lsm_id, u32 op, void __user *buf, >> + size_t size, u32 flags) >> +{ >> + return call_int_hook(lsm_manage_policy, lsm_id, op, buf, size, flags); > > If the LSM doesn't implement this hook, sys_lsm_manage_policy will return 0 > for any inputs, right? This is gonna be so confusing for users. Indeed, that was an oversight. It will return -EOPNOTSUPP in the next patch revision. > > Thanks, > Song Thanks, Maxime