From patchwork Mon May 31 13:11:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 450921 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 13FD3C47082 for ; Mon, 31 May 2021 14:40:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB67260FE5 for ; Mon, 31 May 2021 14:40:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233956AbhEaOlo (ORCPT ); Mon, 31 May 2021 10:41:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:38034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234187AbhEaOjg (ORCPT ); Mon, 31 May 2021 10:39:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 25448613EB; Mon, 31 May 2021 13:52:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622469174; bh=axbAyOi48Hmr3K74CrPJHT6/KFmTBpUvIncWdwiQ5Hk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EMNtBZ/628Os5i9ObpVAxjFOMH/1FXXKt5RLq2gmnuXtg5bCB4FhTYgUzTVxC4OQQ AH8+vg92qJu7rf1cAdYCM06KhgJAIeOMmFB6C6gpvf/Wr4di9N98DTDiLQZ8gbo5Fc fAyytcvcs8OB0CY6/qs7eldLScE9AIAruMcf4si8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sargun Dhillon , Tycho Andersen , Christian Brauner , Kees Cook Subject: [PATCH 5.12 062/296] Documentation: seccomp: Fix user notification documentation Date: Mon, 31 May 2021 15:11:57 +0200 Message-Id: <20210531130705.925373382@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130703.762129381@linuxfoundation.org> References: <20210531130703.762129381@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sargun Dhillon commit aac902925ea646e461c95edc98a8a57eb0def917 upstream. The documentation had some previously incorrect information about how userspace notifications (and responses) were handled due to a change from a previously proposed patchset. Signed-off-by: Sargun Dhillon Acked-by: Tycho Andersen Acked-by: Christian Brauner Signed-off-by: Kees Cook Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210517193908.3113-2-sargun@sargun.me Signed-off-by: Greg Kroah-Hartman --- Documentation/userspace-api/seccomp_filter.rst | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) --- a/Documentation/userspace-api/seccomp_filter.rst +++ b/Documentation/userspace-api/seccomp_filter.rst @@ -250,14 +250,14 @@ Users can read via ``ioctl(SECCOMP_IOCTL seccomp notification fd to receive a ``struct seccomp_notif``, which contains five members: the input length of the structure, a unique-per-filter ``id``, the ``pid`` of the task which triggered this request (which may be 0 if the -task is in a pid ns not visible from the listener's pid namespace), a ``flags`` -member which for now only has ``SECCOMP_NOTIF_FLAG_SIGNALED``, representing -whether or not the notification is a result of a non-fatal signal, and the -``data`` passed to seccomp. Userspace can then make a decision based on this -information about what to do, and ``ioctl(SECCOMP_IOCTL_NOTIF_SEND)`` a -response, indicating what should be returned to userspace. The ``id`` member of -``struct seccomp_notif_resp`` should be the same ``id`` as in ``struct -seccomp_notif``. +task is in a pid ns not visible from the listener's pid namespace). The +notification also contains the ``data`` passed to seccomp, and a filters flag. +The structure should be zeroed out prior to calling the ioctl. + +Userspace can then make a decision based on this information about what to do, +and ``ioctl(SECCOMP_IOCTL_NOTIF_SEND)`` a response, indicating what should be +returned to userspace. The ``id`` member of ``struct seccomp_notif_resp`` should +be the same ``id`` as in ``struct seccomp_notif``. It is worth noting that ``struct seccomp_data`` contains the values of register arguments to the syscall, but does not contain pointers to memory. The task's