From patchwork Wed Jun 17 22:03:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 217642 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E17FEC433E1 for ; Wed, 17 Jun 2020 22:04:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE43721852 for ; Wed, 17 Jun 2020 22:04:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="CyK2Y7jK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727124AbgFQWDg (ORCPT ); Wed, 17 Jun 2020 18:03:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727086AbgFQWDd (ORCPT ); Wed, 17 Jun 2020 18:03:33 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACA28C0613EF for ; Wed, 17 Jun 2020 15:03:32 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id n9so1572031plk.1 for ; Wed, 17 Jun 2020 15:03:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=JfpI1GG/4ASH8XTwm9WwhsnqJPuQkeJ3KfU5iE0siPk=; b=CyK2Y7jKcg3jWb83XP40NF0XUYGVXD+1V+4pT7KZSo4wCLqQ9iB9bRiDEd4nW56PXM hpIQOB7drdivotPmqckm3icsG3S6fJqxUXZUgTWB/JGpBy0Mts6JHOvn0vGN1qiSJx8E A8747kbFVyLgnx3F2OQvdMh3YUSLu0KYMhp+0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=JfpI1GG/4ASH8XTwm9WwhsnqJPuQkeJ3KfU5iE0siPk=; b=MeO9zqdteZAuWCpyBvirJ5p2bSzujetzmzMEG2L6VYqhUQ0aSwufvMk+/w5Yt6mtGS /fJZR7oBQEwlrI6EuabwJlAteNE/0efjHOpAxoyhpIoxUdufgvakw1oUGlgsXtNNqsQk sDDlHiKnl10/MY+DCJOnmDqb/PjZCNS652bagr35tl9Ia1iDkvJzjVFmdTktw/BzGexr LeoAerG01Sb+EUSk0rjJEH7pml9VwveyTgKAEkq3p2D44/acbgvnC6TZACzbaX8pXNCW glBUGSMOdUfoMjgg412Av3dCl/KOMd/+eJbp2qmGK1wtwEmIh0ESbVi0GcaTEdxAVd9/ lEkA== X-Gm-Message-State: AOAM531m3fnLeBCYABUnm8w3NKCdS7ZfHzzh8BhboN1HCwG8d3Gmpi8n k1GNVzpCO/Gvrfo1Dzxn7d3DyQ== X-Google-Smtp-Source: ABdhPJyaT2WGGTn+xIpi/7pv38Ikw5LMtpji1hqM1t34IkAV/SXn2PXvoXUf9SlukpLNRSDtc3ssEA== X-Received: by 2002:a17:90a:d803:: with SMTP id a3mr1130991pjv.125.1592431412195; Wed, 17 Jun 2020 15:03:32 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t201sm755132pfc.104.2020.06.17.15.03.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jun 2020 15:03:30 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Sargun Dhillon , Christian Brauner , Tycho Andersen , David Laight , Christoph Hellwig , "David S. Miller" , Jakub Kicinski , Alexander Viro , Aleksa Sarai , Matt Denton , Jann Horn , Chris Palmer , Robert Sesek , Giuseppe Scrivano , Greg Kroah-Hartman , Andy Lutomirski , Will Drewry , Shuah Khan , netdev@vger.kernel.org, containers@lists.linux-foundation.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v5 3/7] fs: Add fd_install_received() wrapper for __fd_install_received() Date: Wed, 17 Jun 2020 15:03:23 -0700 Message-Id: <20200617220327.3731559-4-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200617220327.3731559-1-keescook@chromium.org> References: <20200617220327.3731559-1-keescook@chromium.org> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org For both pidfd and seccomp, the __user pointer is not used. Update __fd_install_received() to make writing to ufd optional via a NULL check. However, for the fd_install_received_user() wrapper, ufd is NULL checked so an -EFAULT can be returned to avoid changing the SCM_RIGHTS interface behavior. Add new wrapper fd_install_received() for pidfd and seccomp that does not use the ufd argument. For the new helper, the new fd needs to be returned on success. Update the existing callers to handle it. Signed-off-by: Kees Cook --- fs/file.c | 22 ++++++++++++++-------- include/linux/file.h | 7 +++++++ net/compat.c | 2 +- net/core/scm.c | 2 +- 4 files changed, 23 insertions(+), 10 deletions(-) diff --git a/fs/file.c b/fs/file.c index f2167d6feec6..de85a42defe2 100644 --- a/fs/file.c +++ b/fs/file.c @@ -942,9 +942,10 @@ int replace_fd(unsigned fd, struct file *file, unsigned flags) * @o_flags: the O_* flags to apply to the new fd entry * * Installs a received file into the file descriptor table, with appropriate - * checks and count updates. Writes the fd number to userspace. + * checks and count updates. Optionally writes the fd number to userspace, if + * @ufd is non-NULL. * - * Returns -ve on error. + * Returns newly install fd or -ve on error. */ int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_flags) { @@ -960,20 +961,25 @@ int __fd_install_received(struct file *file, int __user *ufd, unsigned int o_fla if (new_fd < 0) return new_fd; - error = put_user(new_fd, ufd); - if (error) { - put_unused_fd(new_fd); - return error; + if (ufd) { + error = put_user(new_fd, ufd); + if (error) { + put_unused_fd(new_fd); + return error; + } } - /* Bump the usage count and install the file. */ + /* Bump the usage count and install the file. The resulting value of + * "error" is ignored here since we only need to take action when + * the file is a socket and testing "sock" for NULL is sufficient. + */ sock = sock_from_file(file, &error); if (sock) { sock_update_netprioidx(&sock->sk->sk_cgrp_data); sock_update_classid(&sock->sk->sk_cgrp_data); } fd_install(new_fd, get_file(file)); - return 0; + return new_fd; } static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) diff --git a/include/linux/file.h b/include/linux/file.h index fe18a1a0d555..e19974ed9322 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -9,6 +9,7 @@ #include #include #include +#include struct file; @@ -96,8 +97,14 @@ extern int __fd_install_received(struct file *file, int __user *ufd, static inline int fd_install_received_user(struct file *file, int __user *ufd, unsigned int o_flags) { + if (ufd == NULL) + return -EFAULT; return __fd_install_received(file, ufd, o_flags); } +static inline int fd_install_received(struct file *file, unsigned int o_flags) +{ + return __fd_install_received(file, NULL, o_flags); +} extern void flush_delayed_fput(void); extern void __fput_sync(struct file *); diff --git a/net/compat.c b/net/compat.c index 94f288e8dac5..71494337cca7 100644 --- a/net/compat.c +++ b/net/compat.c @@ -299,7 +299,7 @@ void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) for (i = 0; i < fdmax; i++) { err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); - if (err) + if (err < 0) break; } diff --git a/net/core/scm.c b/net/core/scm.c index df190f1fdd28..b9a0442ebd26 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -307,7 +307,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) for (i = 0; i < fdmax; i++) { err = fd_install_received_user(scm->fp->fp[i], cmsg_data + i, o_flags); - if (err) + if (err < 0) break; } From patchwork Wed Jun 17 22:03:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 217644 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92997C433DF for ; Wed, 17 Jun 2020 22:03:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 701C721548 for ; Wed, 17 Jun 2020 22:03:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="AssCNT+f" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727083AbgFQWDd (ORCPT ); Wed, 17 Jun 2020 18:03:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727063AbgFQWDc (ORCPT ); Wed, 17 Jun 2020 18:03:32 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20007C0613EE for ; Wed, 17 Jun 2020 15:03:32 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id m2so1718145pjv.2 for ; Wed, 17 Jun 2020 15:03:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=d7bw5q/TJxpqMicrHyIFon0t9gt+svhVPDuc7AUFnrI=; b=AssCNT+fl7FZXIZEydCky+FoEabK9WHSRC/Cz7t+GsLm7aO2UJ/YytOxHd1B0j1e+l XnLm1Rt+qfp2EUmGG/yFhjq91D26f7ku2eo0bUwGuEdGWnmwt6HPJOj85Snm44Eef3sC VVnAeX1Tp5FyYfkxWhsd8A7EzPvh9OS4GeLdE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=d7bw5q/TJxpqMicrHyIFon0t9gt+svhVPDuc7AUFnrI=; b=k/GM4MEdi0JYBYir9DeNw/z3zqP4UH8mEepTI7DRZ4A2l8Zdp8WQWNafzzU7prDS1B 5wEziiI78t+8JlCfGpbqMmMKvHKPLU7pZDaE7WeCvCfQvY9p1Xw6U+yg/yaVaDXtER02 r/UaC34Bht/Cae0fqvR2FJWv+3lvC52Ub5TXuk29dTuhXTlgFMWS9fvqt0bY6SCYkQ6n B16Ua/0IuhjEfeeIuPMAyOWbWlj5Z3cIOEqlQxvMEEjJTFmwakfvWw1rpkPekhCJ3f6Z TM+WylF20Nek/sSjk3JUFKG+GC9umGpwSkguepOuSXqRWkQuZXKLjVTyrUR5XCbL8LMg 1xww== X-Gm-Message-State: AOAM5325Fg//Mc5Ued85Fr7uY1ZEv+dAiWlcWbQB9ipfhhIUUJ/bliEF N87nFawdLZSlMnRWxEHHPpyFcw== X-Google-Smtp-Source: ABdhPJy8S/6IprS//E4loSZ1ZgKk4AjU+iw9QdwwDUrpFc38iJU+1J4kMZ7xNS+1rFNTzrhm1LjJ3w== X-Received: by 2002:a17:90a:f3c4:: with SMTP id ha4mr1155509pjb.18.1592431411577; Wed, 17 Jun 2020 15:03:31 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id n24sm461968pjt.47.2020.06.17.15.03.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jun 2020 15:03:30 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Sargun Dhillon , Christian Brauner , Tycho Andersen , David Laight , Christoph Hellwig , "David S. Miller" , Jakub Kicinski , Alexander Viro , Aleksa Sarai , Matt Denton , Jann Horn , Chris Palmer , Robert Sesek , Giuseppe Scrivano , Greg Kroah-Hartman , Andy Lutomirski , Will Drewry , Shuah Khan , netdev@vger.kernel.org, containers@lists.linux-foundation.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v5 4/7] pidfd: Replace open-coded partial fd_install_received() Date: Wed, 17 Jun 2020 15:03:24 -0700 Message-Id: <20200617220327.3731559-5-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200617220327.3731559-1-keescook@chromium.org> References: <20200617220327.3731559-1-keescook@chromium.org> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The sock counting (sock_update_netprioidx() and sock_update_classid()) was missing from pidfd's implementation of received fd installation. Replace the open-coded version with a call to the new fd_install_received() helper. Fixes: 8649c322f75c ("pid: Implement pidfd_getfd syscall") Signed-off-by: Kees Cook --- kernel/pid.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) diff --git a/kernel/pid.c b/kernel/pid.c index f1496b757162..24924ec5df0e 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -635,18 +635,9 @@ static int pidfd_getfd(struct pid *pid, int fd) if (IS_ERR(file)) return PTR_ERR(file); - ret = security_file_receive(file); - if (ret) { - fput(file); - return ret; - } - - ret = get_unused_fd_flags(O_CLOEXEC); + ret = fd_install_received(file, O_CLOEXEC); if (ret < 0) fput(file); - else - fd_install(ret, file); - return ret; } From patchwork Wed Jun 17 22:03:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 217643 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51831C433E0 for ; Wed, 17 Jun 2020 22:03:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27B2921852 for ; Wed, 17 Jun 2020 22:03:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="THJBRTFw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727816AbgFQWDr (ORCPT ); Wed, 17 Jun 2020 18:03:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727784AbgFQWDj (ORCPT ); Wed, 17 Jun 2020 18:03:39 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EBB5C0617BB for ; Wed, 17 Jun 2020 15:03:36 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id 10so1796940pfx.8 for ; Wed, 17 Jun 2020 15:03:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=s6nxy7AwZGtoql+LbUkBHllnwgWYj58mW1sDysdJ1vg=; b=THJBRTFwPqKrgTynwdqc6tP63XYizHMXDJ/tpFigmCgXKT9ywN0gTaISfScTuCIoXX ELo2H8FGafq7E4i3aK7qj7GodIAF0JTxZI1VuLgPj8LasDHq26PRD5qXlgn9cfw3XycB bTYPGsFKBTK0Nfzl/tNhQLb7qAEbwTILjsSUk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=s6nxy7AwZGtoql+LbUkBHllnwgWYj58mW1sDysdJ1vg=; b=rSXtRLWKXAxbXO5MkkglWSbj2pDZcet8KJoMbw4icMLuTjjfxSqb7W9S1pwYl9tv25 8zyGKmVye0sfCdLqlCc71pXMCOZdzIs8iuupe2CqkoF4ZwuovBj5Lg26D3uSP95heU1c HHug2a7ZqLX9WQAFfKeWSHew13qnqB6lMg/jYYE+8T/zKf8KU/bUW8kZ0JcxVVKZg4lP iIDdfReCkgZ9Kfubv7NAk4shZKCd9splUiBolbNSpXbhO7DVrxaMs4bD7jHmVn5BtFgl sdP3LrXkckxpJ5lhV6MD/ZhiRfQlLzX9TZJ2XlGauEFmTkRecQl5H0aHuV+n2BX9dvQH X9dA== X-Gm-Message-State: AOAM532/lJIMyFXXBmbulqzK8dAc62xZEseEqwoUqW2ODJ5wcZSdIqqy Sb/o1FADYWoOmzyDsL4BPGW2gg== X-Google-Smtp-Source: ABdhPJxS49EBdf4oJlb/sifNaCdN+lj0qN/PquPppLJoOyakXqU7DF9KsQu4IE6nNJB5iuBJQB4ZyQ== X-Received: by 2002:a63:205b:: with SMTP id r27mr770691pgm.326.1592431415799; Wed, 17 Jun 2020 15:03:35 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id d22sm682059pgh.64.2020.06.17.15.03.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Jun 2020 15:03:34 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Sargun Dhillon , Christian Brauner , Tycho Andersen , David Laight , Christoph Hellwig , "David S. Miller" , Jakub Kicinski , Alexander Viro , Aleksa Sarai , Matt Denton , Jann Horn , Chris Palmer , Robert Sesek , Giuseppe Scrivano , Greg Kroah-Hartman , Andy Lutomirski , Will Drewry , Shuah Khan , netdev@vger.kernel.org, containers@lists.linux-foundation.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v5 7/7] selftests/seccomp: Test SECCOMP_IOCTL_NOTIF_ADDFD Date: Wed, 17 Jun 2020 15:03:27 -0700 Message-Id: <20200617220327.3731559-8-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200617220327.3731559-1-keescook@chromium.org> References: <20200617220327.3731559-1-keescook@chromium.org> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Sargun Dhillon Test whether we can add file descriptors in response to notifications. This injects the file descriptors via notifications, and then uses kcmp to determine whether or not it has been successful. It also includes some basic sanity checking for arguments. Signed-off-by: Sargun Dhillon Link: https://lore.kernel.org/r/20200603011044.7972-5-sargun@sargun.me Co-developed-by: Kees Cook Signed-off-by: Kees Cook --- tools/testing/selftests/seccomp/seccomp_bpf.c | 229 ++++++++++++++++++ 1 file changed, 229 insertions(+) diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 4e1891f8a0cd..143eafdc4fdc 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include @@ -168,7 +169,9 @@ struct seccomp_metadata { #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3) +#endif +#ifndef SECCOMP_RET_USER_NOTIF #define SECCOMP_RET_USER_NOTIF 0x7fc00000U #define SECCOMP_IOC_MAGIC '!' @@ -204,6 +207,39 @@ struct seccomp_notif_sizes { }; #endif +#ifndef SECCOMP_IOCTL_NOTIF_ADDFD +/* On success, the return value is the remote process's added fd number */ +#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ + struct seccomp_notif_addfd) + +/* valid flags for seccomp_notif_addfd */ +#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ + +struct seccomp_notif_addfd { + __u64 id; + __u32 flags; + __u32 srcfd; + __u32 newfd; + __u32 newfd_flags; +}; +#endif + +struct seccomp_notif_addfd_small { + __u64 id; + char weird[4]; +}; +#define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \ + SECCOMP_IOW(3, struct seccomp_notif_addfd_small) + +struct seccomp_notif_addfd_big { + union { + struct seccomp_notif_addfd addfd; + char buf[sizeof(struct seccomp_notif_addfd) + 8]; + }; +}; +#define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \ + SECCOMP_IOWR(3, struct seccomp_notif_addfd_big) + #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2 @@ -3833,6 +3869,199 @@ TEST(user_notification_filter_empty_threaded) EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); } +TEST(user_notification_addfd) +{ + pid_t pid; + long ret; + int status, listener, memfd, fd; + struct seccomp_notif_addfd addfd = {}; + struct seccomp_notif_addfd_small small = {}; + struct seccomp_notif_addfd_big big = {}; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + /* 100 ms */ + struct timespec delay = { .tv_nsec = 100000000 }; + + memfd = memfd_create("test", 0); + ASSERT_GE(memfd, 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) + exit(1); + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + } + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + addfd.srcfd = memfd; + addfd.newfd = 0; + addfd.id = req.id; + addfd.flags = 0x0; + + /* Verify bad newfd_flags cannot be set */ + addfd.newfd_flags = ~O_CLOEXEC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.newfd_flags = O_CLOEXEC; + + /* Verify bad flags cannot be set */ + addfd.flags = 0xff; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.flags = 0; + + /* Verify that remote_fd cannot be set without setting flags */ + addfd.newfd = 1; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.newfd = 0; + + /* Verify small size cannot be set */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1); + EXPECT_EQ(errno, EINVAL); + + /* Verify we can't send bits filled in unknown buffer area */ + memset(&big, 0xAA, sizeof(big)); + big.addfd = addfd; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1); + EXPECT_EQ(errno, E2BIG); + + + /* Verify we can set an arbitrary remote fd */ + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + /* + * The child has fds 0(stdin), 1(stdout), 2(stderr), 3(memfd), + * 4(listener), so the newly allocated fd should be 5. + */ + EXPECT_EQ(fd, 5); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* Verify we can set an arbitrary remote fd with large size */ + memset(&big, 0x0, sizeof(big)); + big.addfd = addfd; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); + EXPECT_EQ(fd, 6); + + /* Verify we can set a specific remote fd */ + addfd.newfd = 42; + addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + EXPECT_EQ(fd, 42); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* Resume syscall */ + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* + * This sets the ID of the ADD FD to the last request plus 1. The + * notification ID increments 1 per notification. + */ + addfd.id = req.id + 1; + + /* This spins until the underlying notification is generated */ + while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && + errno != -EINPROGRESS) + nanosleep(&delay, NULL); + + memset(&req, 0, sizeof(req)); + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + ASSERT_EQ(addfd.id, req.id); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* Wait for child to finish. */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + close(memfd); +} + +TEST(user_notification_addfd_rlimit) +{ + pid_t pid; + long ret; + int status, listener, memfd; + struct seccomp_notif_addfd addfd = {}; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + const struct rlimit lim = { + .rlim_cur = 0, + .rlim_max = 0, + }; + + memfd = memfd_create("test", 0); + ASSERT_GE(memfd, 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0); + + addfd.srcfd = memfd; + addfd.newfd_flags = O_CLOEXEC; + addfd.newfd = 0; + addfd.id = req.id; + addfd.flags = 0; + + /* Should probably spot check /proc/sys/fs/file-nr */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EMFILE); + + addfd.newfd = 100; + addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EBADF); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* Wait for child to finish. */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + close(memfd); +} + /* * TODO: * - expand NNP testing