From patchwork Fri Dec 9 16:04:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Xu X-Patchwork-Id: 31867 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp861544wrr; Fri, 9 Dec 2022 08:09:26 -0800 (PST) X-Google-Smtp-Source: AA0mqf6TQUln9YI4eCeVuJL8c5U2nfcPZn480V1T2LWPP7bMCV+NCQloWF68OGlzswXM4f1MzvjL X-Received: by 2002:a17:903:1341:b0:189:e4e:792c with SMTP id jl1-20020a170903134100b001890e4e792cmr5826550plb.64.1670602166009; Fri, 09 Dec 2022 08:09:26 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1670602165; cv=none; d=google.com; s=arc-20160816; b=cOiep+Yu4y5N1nzP48TbRa8WEzEgF6N0DZx6N3T9VPg5ovWdAYFaY/lZaC6QRZfvuy gh/DJ5i33MmaT809FLsBBcjVIglLX636Uk8fLaHFJvMMC1q2fMOINKCyk5mcrfGoB/Ee wUnu7e0z65YZhxkUlr6aBIs4GZNYTOzHC2JdIzjVyDMLCQxN10TqGqp0YGf/xsmopzor x/jJ1y9V+JX7nt1SL4gOAy8I2cYFe7H7YpAc+ubydAKsXPlkIpfMmFxSIcu8qsZ0zZ9R oDNZxpkp4nPng2poS9/KUmpx9FrJwKFj42CXtx067idPul1ZhRW4xkwbZSh57tL2qQjJ TRvw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=dO2vEZu0Db7wP8hwByIkT/4WBK5RsSRu/0g8CrsVk0Q=; b=j8en01ZeJ10+XP92liu5Qd2QKrfzf/IeFVfLLiAVLcA44luzNxYG02XVec+LHfnlZ2 CiQDySsNjSGnLeSG6NqI8OxTLCWJqpu2nz2Nj/8fX5M/AebKkh7+ZM1MqXcTuD9rnVgk 4mivp66U5avKyH8R9zXBk1tAnQwn02FSadryXhXLdXMJeajUKyvmljLvHuc3x7lfA4NE javfzkMLaMnJdeSxnlO44uOd5124LjFVebt5o9+d/1+ECIwzUP4fRBvXMnJzhfqcr2hZ 5n7rQ0cLqxv2UTFjBfvS6ncUkwX1fITuWtZk6/c92wHchyKnopBVilialgzp9nTNJtzi GVsg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=Nz9hhcL5; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id u4-20020a170902e5c400b001894d872b14si1836359plf.66.2022.12.09.08.09.12; Fri, 09 Dec 2022 08:09:25 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@chromium.org header.s=google header.b=Nz9hhcL5; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=chromium.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230100AbiLIQFq (ORCPT + 99 others); Fri, 9 Dec 2022 11:05:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230161AbiLIQFY (ORCPT ); Fri, 9 Dec 2022 11:05:24 -0500 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A59359FDD for ; Fri, 9 Dec 2022 08:05:06 -0800 (PST) Received: by mail-pg1-x52e.google.com with SMTP id s196so3827191pgs.3 for ; Fri, 09 Dec 2022 08:05:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=dO2vEZu0Db7wP8hwByIkT/4WBK5RsSRu/0g8CrsVk0Q=; b=Nz9hhcL5VUT1DNeWW7Mvl2m+8tMK4KUW9ZM63sJBU7BZC5BXcP0QrGhhfixxQYFJr6 jaW0mxnuLY9YKm9/eIJoGL3j7a2Nnz/LO5wqZBulnXeLBCJR0YvayQPJuPVgnkWRqUzs VIPCWg63G260HdzCt34cupUwQj6+eayz1j76w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=dO2vEZu0Db7wP8hwByIkT/4WBK5RsSRu/0g8CrsVk0Q=; b=o/YGGuR0Rzoid6Z6/N+Sy6HFPP/LsWmjH3NFFSJGjJfD5hPziGtx08BYrSUZcAr8mk fLRd7gcPTdE5D+iN1/kgmVvS2ta96XIVm82mrqrrnhPbj9TMv4Tnkues7X5CrlGaY8wq hv2TITF2PVfTDm9CHV+JRRgS+UZmk3G5a9Lzx9igihIVY6rLvSiUb2fDX81rCuT3YWSp otcoa05Znli1QOGws/XNnnwBAUgLrYZJnqJ2cWvJXp0iTam39BrP5a6+oO2XY0qxH83Z Xa8ClSpyIMgdIHb3K4836RpwnGlIpWdObKwlbXiAnJAyOIGZTL5HF5+Vv6um/mR3pqM3 vgnQ== X-Gm-Message-State: ANoB5pl4/ydI/e9g8Yi0lEVK5xdqJEj36MJEmcZx/txK8r3bT5UIqaGu fxLfh1xsQ71rfcpKXuviYSkncA== X-Received: by 2002:aa7:858a:0:b0:575:de28:b1f4 with SMTP id w10-20020aa7858a000000b00575de28b1f4mr5165976pfn.16.1670601905655; Fri, 09 Dec 2022 08:05:05 -0800 (PST) Received: from jeffxud.c.googlers.com.com (30.202.168.34.bc.googleusercontent.com. [34.168.202.30]) by smtp.gmail.com with ESMTPSA id a15-20020aa795af000000b00576670cc170sm1460504pfk.93.2022.12.09.08.05.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Dec 2022 08:05:05 -0800 (PST) From: jeffxu@chromium.org To: skhan@linuxfoundation.org, keescook@chromium.org Cc: akpm@linux-foundation.org, dmitry.torokhov@gmail.com, dverkamp@chromium.org, hughd@google.com, jeffxu@google.com, jorgelo@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, jannh@google.com, linux-hardening@vger.kernel.org, linux-security-module@vger.kernel.org, kernel test robot Subject: [PATCH v7 6/6] mm/memfd: security hook for memfd_create Date: Fri, 9 Dec 2022 16:04:53 +0000 Message-Id: <20221209160453.3246150-7-jeffxu@google.com> X-Mailer: git-send-email 2.39.0.rc1.256.g54fd8350bd-goog In-Reply-To: <20221209160453.3246150-1-jeffxu@google.com> References: <20221209160453.3246150-1-jeffxu@google.com> MIME-Version: 1.0 X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1751753336692368982?= X-GMAIL-MSGID: =?utf-8?q?1751753336692368982?= From: Jeff Xu The new security_memfd_create allows lsm to check flags of memfd_create. The security by default system (such as chromeos) can use this to implement system wide lsm to allow only non-executable memfd being created. Signed-off-by: Jeff Xu Reported-by: kernel test robot --- include/linux/lsm_hook_defs.h | 1 + include/linux/lsm_hooks.h | 4 ++++ include/linux/security.h | 6 ++++++ mm/memfd.c | 5 +++++ security/security.c | 5 +++++ 5 files changed, 21 insertions(+) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index ec119da1d89b..fd40840927c8 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -164,6 +164,7 @@ LSM_HOOK(int, 0, file_alloc_security, struct file *file) LSM_HOOK(void, LSM_RET_VOID, file_free_security, struct file *file) LSM_HOOK(int, 0, file_ioctl, struct file *file, unsigned int cmd, unsigned long arg) +LSM_HOOK(int, 0, memfd_create, char *name, unsigned int flags) LSM_HOOK(int, 0, mmap_addr, unsigned long addr) LSM_HOOK(int, 0, mmap_file, struct file *file, unsigned long reqprot, unsigned long prot, unsigned long flags) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 4ec80b96c22e..5a18a6552278 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -543,6 +543,10 @@ * simple integer value. When @arg represents a user space pointer, it * should never be used by the security module. * Return 0 if permission is granted. + * @memfd_create: + * @name is the name of memfd file. + * @flags is the flags used in memfd_create. + * Return 0 if permission is granted. * @mmap_addr : * Check permissions for a mmap operation at @addr. * @addr contains virtual address that will be used for the operation. diff --git a/include/linux/security.h b/include/linux/security.h index ca1b7109c0db..5b87a780822a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -384,6 +384,7 @@ int security_file_permission(struct file *file, int mask); int security_file_alloc(struct file *file); void security_file_free(struct file *file); int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg); +int security_memfd_create(char *name, unsigned int flags); int security_mmap_file(struct file *file, unsigned long prot, unsigned long flags); int security_mmap_addr(unsigned long addr); @@ -963,6 +964,11 @@ static inline int security_file_ioctl(struct file *file, unsigned int cmd, return 0; } +static inline int security_memfd_create(char *name, unsigned int flags) +{ + return 0; +} + static inline int security_mmap_file(struct file *file, unsigned long prot, unsigned long flags) { diff --git a/mm/memfd.c b/mm/memfd.c index 92f0a5765f7c..f04ed5f0474f 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -356,6 +356,11 @@ SYSCALL_DEFINE2(memfd_create, goto err_name; } + /* security hook for memfd_create */ + error = security_memfd_create(name, flags); + if (error) + return error; + if (flags & MFD_HUGETLB) { file = hugetlb_file_setup(name, 0, VM_NORESERVE, HUGETLB_ANONHUGE_INODE, diff --git a/security/security.c b/security/security.c index 79d82cb6e469..57788cf94075 100644 --- a/security/security.c +++ b/security/security.c @@ -1010,6 +1010,11 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb, } EXPORT_SYMBOL(security_sb_clone_mnt_opts); +int security_memfd_create(char *name, unsigned int flags) +{ + return call_int_hook(memfd_create, 0, name, flags); +} + int security_move_mount(const struct path *from_path, const struct path *to_path) { return call_int_hook(move_mount, 0, from_path, to_path);