From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A17BAC001B0 for ; Thu, 10 Aug 2023 15:56:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233374AbjHJP4U (ORCPT ); Thu, 10 Aug 2023 11:56:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232447AbjHJP4T (ORCPT ); Thu, 10 Aug 2023 11:56:19 -0400 Received: from smtp-relay-canonical-1.canonical.com (smtp-relay-canonical-1.canonical.com [185.125.188.121]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33A672112; Thu, 10 Aug 2023 08:56:19 -0700 (PDT) Received: from [192.168.192.83] (unknown [50.47.134.245]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id 927C93F5DF; Thu, 10 Aug 2023 15:56:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1691682978; bh=xXs67xX5eSem2DETtWFAM143oEDYupG/6NmY4oyGPuU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kjhBUMlEKOL2vJHymABDSXeLBoUmIOk7iLA4A02yBkPjHaYm362FlhNjxDeyYIZp4 UpiGCO6H9r2G71WK4PBUcwMrLxeb3D8EBqRFAZ/shdc4OxiosE6Mhjm/wmgQeZI/s0 6NoHUwAWq/M36eseVH+yPAdr92uLxeJ7HkvQ41TL3Go85Jd0Uj1X7r8Qgo2T5wmvX0 8B9NFBmCFxBkv1lUcthSNfUXOwodeTB5Jnzce0mnthkSeA9Nq6fWqViP8ThDWP2nqZ QWJHeQ+7iMx4X2+07llB6gxZqYc5NA/FtLcdJSW/limd/GMwLo2hRpoDuYGUmZ0vkb YOOg3JyKwCCNw== Message-ID: <8aaac853-719b-f182-4a66-e4422de2cdf0@canonical.com> Date: Thu, 10 Aug 2023 08:55:46 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v13 05/11] LSM: Create lsm_list_modules system call Content-Language: en-US To: Casey Schaufler , paul@paul-moore.com, linux-security-module@vger.kernel.org Cc: jmorris@namei.org, serge@hallyn.com, keescook@chromium.org, penguin-kernel@i-love.sakura.ne.jp, stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, mic@digikod.net References: <20230802174435.11928-1-casey@schaufler-ca.com> <20230802174435.11928-6-casey@schaufler-ca.com> From: John Johansen Organization: Canonical In-Reply-To: <20230802174435.11928-6-casey@schaufler-ca.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: On 8/2/23 10:44, Casey Schaufler wrote: > Create a system call to report the list of Linux Security Modules > that are active on the system. The list is provided as an array > of LSM ID numbers. > > The calling application can use this list determine what LSM > specific actions it might take. That might include choosing an > output format, determining required privilege or bypassing > security module specific behavior. > > Signed-off-by: Casey Schaufler > Reviewed-by: Kees Cook > Reviewed-by: Serge Hallyn Reviewed-by: John Johansen > --- > Documentation/userspace-api/lsm.rst | 3 +++ > include/linux/syscalls.h | 1 + > kernel/sys_ni.c | 1 + > security/lsm_syscalls.c | 39 +++++++++++++++++++++++++++++ > 4 files changed, 44 insertions(+) > > diff --git a/Documentation/userspace-api/lsm.rst b/Documentation/userspace-api/lsm.rst > index f8499f3e2826..a76da373841b 100644 > --- a/Documentation/userspace-api/lsm.rst > +++ b/Documentation/userspace-api/lsm.rst > @@ -63,6 +63,9 @@ Get the specified security attributes of the current process > .. kernel-doc:: security/lsm_syscalls.c > :identifiers: sys_lsm_get_self_attr > > +.. kernel-doc:: security/lsm_syscalls.c > + :identifiers: sys_lsm_list_modules > + > Additional documentation > ======================== > > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > index a3938850752a..4e1596b5c300 100644 > --- a/include/linux/syscalls.h > +++ b/include/linux/syscalls.h > @@ -958,6 +958,7 @@ asmlinkage long sys_lsm_get_self_attr(unsigned int attr, struct lsm_ctx *ctx, > size_t *size, __u32 flags); > asmlinkage long sys_lsm_set_self_attr(unsigned int attr, struct lsm_ctx *ctx, > size_t size, __u32 flags); > +asmlinkage long sys_lsm_list_modules(u64 *ids, size_t *size, u32 flags); > > /* > * Architecture-specific system calls > diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c > index 8b96cd01b485..7663ef16c07e 100644 > --- a/kernel/sys_ni.c > +++ b/kernel/sys_ni.c > @@ -172,6 +172,7 @@ COND_SYSCALL(fadvise64_64); > COND_SYSCALL_COMPAT(fadvise64_64); > COND_SYSCALL(lsm_get_self_attr); > COND_SYSCALL(lsm_set_self_attr); > +COND_SYSCALL(lsm_list_modules); > > /* CONFIG_MMU only */ > COND_SYSCALL(swapon); > diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c > index ee3881159241..f03f2d17ab49 100644 > --- a/security/lsm_syscalls.c > +++ b/security/lsm_syscalls.c > @@ -53,3 +53,42 @@ SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *, > { > return security_getselfattr(attr, ctx, size, flags); > } > + > +/** > + * sys_lsm_list_modules - Return a list of the active security modules > + * @ids: the LSM module ids > + * @size: pointer to size of @ids, updated on return > + * @flags: reserved for future use, must be zero > + * > + * Returns a list of the active LSM ids. On success this function > + * returns the number of @ids array elements. This value may be zero > + * if there are no LSMs active. If @size is insufficient to contain > + * the return data -E2BIG is returned and @size is set to the minimum > + * required size. In all other cases a negative value indicating the > + * error is returned. > + */ > +SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, size_t __user *, size, > + u32, flags) > +{ > + size_t total_size = lsm_active_cnt * sizeof(*ids); > + size_t usize; > + int i; > + > + if (flags) > + return -EINVAL; > + > + if (get_user(usize, size)) > + return -EFAULT; > + > + if (put_user(total_size, size) != 0) > + return -EFAULT; > + > + if (usize < total_size) > + return -E2BIG; > + > + for (i = 0; i < lsm_active_cnt; i++) > + if (put_user(lsm_idlist[i]->id, ids++)) > + return -EFAULT; > + > + return lsm_active_cnt; > +}