From patchwork Wed Jul 24 02:06:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 13740543 X-Patchwork-Delegate: paul@paul-moore.com Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 39CE8BA47; Wed, 24 Jul 2024 01:56:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721786217; cv=none; b=j0i5sE3TrzYqZVppx8WG6JBbbLXn4KFr7z1c6i9FQ4PgxkOs2SDnRQgCFJkYIlQO0h7rJXSzmavoSzPrBOj0wXbuwXL17k7hr5+B6iYOn/sz8ju3uCzI8k55M5ZX10uERFY5EifE/TDCqzuEI2MjJr/ZNFiTZ73C/enXnvOWINI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721786217; c=relaxed/simple; bh=5DRU7wCB037mq/JvSTnFtR6YaqJrWFenXiKBaslAv5I=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=VjqgK/mopgR6tjONP7D+1JXiCltDyrqpO3If2UNsvomVi47q5I0S9Ju5j8KsJ4lVvge3FIcrVMFwK8RtTS+9xWD/8z5R+BHDE+YlcVWpSG55DdjQIHytGuGuewdfDEFw9w5hMlwXZaqWsIAefIt/xlzu2crO3RjjRk/O3a1bOEM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4WTHF34txPz4f3jsV; Wed, 24 Jul 2024 09:56:39 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id 15F781A0359; Wed, 24 Jul 2024 09:56:52 +0800 (CST) Received: from k01.huawei.com (unknown [10.67.174.197]) by APP1 (Coremail) with SMTP id cCh0CgDXw3VgX6BmaKTZAw--.12072S3; Wed, 24 Jul 2024 09:56:51 +0800 (CST) From: Xu Kuohai To: linux-security-module@vger.kernel.org, selinux@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-integrity@vger.kernel.org Cc: Paul Moore , Casey Schaufler , "Serge E . Hallyn" , Miklos Szeredi , Amir Goldstein , James Morris , Mimi Zohar , Roberto Sassu , Dmitry Kasatkin , Eric Snowberg , Stephen Smalley , Ondrej Mosnacek Subject: [PATCH v1 1/2] lsm: Refactor return value of LSM hook vm_enough_memory Date: Wed, 24 Jul 2024 10:06:58 +0800 Message-Id: <20240724020659.120353-2-xukuohai@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240724020659.120353-1-xukuohai@huaweicloud.com> References: <20240724020659.120353-1-xukuohai@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: cCh0CgDXw3VgX6BmaKTZAw--.12072S3 X-Coremail-Antispam: 1UD129KBjvJXoWxur48GF1DAw17Kr47ur1rWFg_yoW7Gr1UpF 4rKa13KrWvkFyxWrs7GanxC3W3t34fWF4UKrWUu34Fk3ZFvr17KF4UA3s0kr17trW8tasF qFW29rs3C3Wqq37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPFb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGw A2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AFwI 0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG 67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MI IYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E 14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU2HGQ DUUUU X-CM-SenderInfo: 50xn30hkdlqx5xdzvxpfor3voofrz/ From: Xu Kuohai To be consistent with most LSM hooks, convert the return value of hook vm_enough_memory to 0 or a negative error code. Before: - Hook vm_enough_memory returns 1 if permission is granted, 0 if not. - LSM_RET_DEFAULT(vm_enough_memory_mm) is 1. After: - Hook vm_enough_memory reutrns 0 if permission is granted, negative error code if not. - LSM_RET_DEFAULT(vm_enough_memory_mm) is 0. Signed-off-by: Xu Kuohai --- include/linux/lsm_hook_defs.h | 2 +- include/linux/security.h | 2 +- security/commoncap.c | 11 +++-------- security/security.c | 11 +++++------ security/selinux/hooks.c | 15 ++++----------- 5 files changed, 14 insertions(+), 27 deletions(-) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 1d113a727098..06265e70013c 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -48,7 +48,7 @@ LSM_HOOK(int, 0, quota_on, struct dentry *dentry) LSM_HOOK(int, 0, syslog, int type) LSM_HOOK(int, 0, settime, const struct timespec64 *ts, const struct timezone *tz) -LSM_HOOK(int, 1, vm_enough_memory, struct mm_struct *mm, long pages) +LSM_HOOK(int, 0, vm_enough_memory, struct mm_struct *mm, long pages) LSM_HOOK(int, 0, bprm_creds_for_exec, struct linux_binprm *bprm) LSM_HOOK(int, 0, bprm_creds_from_file, struct linux_binprm *bprm, const struct file *file) LSM_HOOK(int, 0, bprm_check_security, struct linux_binprm *bprm) diff --git a/include/linux/security.h b/include/linux/security.h index 21cf70346b33..ed4deff36fff 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -634,7 +634,7 @@ static inline int security_settime64(const struct timespec64 *ts, static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) { - return __vm_enough_memory(mm, pages, cap_vm_enough_memory(mm, pages)); + return __vm_enough_memory(mm, pages, !cap_vm_enough_memory(mm, pages)); } static inline int security_bprm_creds_for_exec(struct linux_binprm *bprm) diff --git a/security/commoncap.c b/security/commoncap.c index 162d96b3a676..cefad323a0b1 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1396,17 +1396,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * Determine whether the allocation of a new virtual mapping by the current * task is permitted. * - * Return: 1 if permission is granted, 0 if not. + * Return: 0 if permission granted, negative error code if not. */ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { - int cap_sys_admin = 0; - - if (cap_capable(current_cred(), &init_user_ns, - CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) == 0) - cap_sys_admin = 1; - - return cap_sys_admin; + return cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN, + CAP_OPT_NOAUDIT); } /** diff --git a/security/security.c b/security/security.c index 12e402b7230f..ff5cca992ee1 100644 --- a/security/security.c +++ b/security/security.c @@ -1218,15 +1218,14 @@ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages) int rc; /* - * The module will respond with a positive value if - * it thinks the __vm_enough_memory() call should be - * made with the cap_sys_admin set. If all of the modules - * agree that it should be set it will. If any module - * thinks it should not be set it won't. + * The module will respond with 0 if it thinks the __vm_enough_memory() + * call should be made with the cap_sys_admin set. If all of the modules + * agree that it should be set it will. If any module thinks it should + * not be set it won't. */ lsm_for_each_hook(scall, vm_enough_memory) { rc = scall->hl->hook.vm_enough_memory(mm, pages); - if (rc <= 0) { + if (rc < 0) { cap_sys_admin = 0; break; } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 0939816e9671..af7467cdd181 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2202,23 +2202,16 @@ static int selinux_syslog(int type) } /* - * Check that a process has enough memory to allocate a new virtual - * mapping. 0 means there is enough memory for the allocation to - * succeed and -ENOMEM implies there is not. + * Check permission for allocating a new virtual mapping. Returns + * 0 if permission is granted, negative error code if not. * * Do not audit the selinux permission check, as this is applied to all * processes that allocate mappings. */ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) { - int rc, cap_sys_admin = 0; - - rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, - CAP_OPT_NOAUDIT, true); - if (rc == 0) - cap_sys_admin = 1; - - return cap_sys_admin; + return cred_has_capability(current_cred(), CAP_SYS_ADMIN, + CAP_OPT_NOAUDIT, true); } /* binprm security operations */