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 EDE49C4332F for ; Fri, 16 Dec 2022 16:45:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229777AbiLPQo7 (ORCPT ); Fri, 16 Dec 2022 11:44:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231718AbiLPQoM (ORCPT ); Fri, 16 Dec 2022 11:44:12 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BD112E687; Fri, 16 Dec 2022 08:43:46 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id B54D234588; Fri, 16 Dec 2022 16:43:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1671209024; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=odwET7RAJt4TyX2c0eIiYppqthEh1UCsaW9+/jL2kns=; b=xWkCYvJJcIhuomKFa0qbKF1b6jKhBc1nCaqwf4rU8Qfy/aQkvwRuxlvgINu/W5XshFcpqs aVsg5AJWBVVLpyUdkZldHi2HJmGc03v4KoK/MT1VgPs12LKde+BPU3kcVpkybg+K7ZnbwP 7aF9Z/wTytEZoYCIkEQHur57R16mLz4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1671209024; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=odwET7RAJt4TyX2c0eIiYppqthEh1UCsaW9+/jL2kns=; b=mhw6SA5W7W6VoFVGnzby+z7jJ3LSIG35U7TS/KxzU4sQbpJQocr/N2KgUgniszDZLULex2 lzOiaOVGNrGgjPDw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 8C3AD138FD; Fri, 16 Dec 2022 16:43:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id mr41IkCgnGOILgAAMHmgww (envelope-from ); Fri, 16 Dec 2022 16:43:44 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id 894A4A0762; Fri, 16 Dec 2022 17:43:42 +0100 (CET) Date: Fri, 16 Dec 2022 17:43:42 +0100 From: Jan Kara To: Richard Guy Briggs Cc: Linux-Audit Mailing List , LKML , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, Paul Moore , Eric Paris , Steve Grubb , Jan Kara , Amir Goldstein Subject: Re: [PATCH v5 2/3] fanotify: define struct members to hold response decision context Message-ID: <20221216164342.ojcbdifdmafq5njw@quack3> References: <45da8423b9b1e8fc7abd68cd2269acff8cf9022a.1670606054.git.rgb@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45da8423b9b1e8fc7abd68cd2269acff8cf9022a.1670606054.git.rgb@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Mon 12-12-22 09:06:10, Richard Guy Briggs wrote: > This patch adds a flag, FAN_INFO and an extensible buffer to provide > additional information about response decisions. The buffer contains > one or more headers defining the information type and the length of the > following information. The patch defines one additional information > type, FAN_RESPONSE_INFO_AUDIT_RULE, to audit a rule number. This will > allow for the creation of other information types in the future if other > users of the API identify different needs. > > Suggested-by: Steve Grubb > Link: https://lore.kernel.org/r/2745105.e9J7NaK4W3@x2 > Suggested-by: Jan Kara > Link: https://lore.kernel.org/r/20201001101219.GE17860@quack2.suse.cz > Signed-off-by: Richard Guy Briggs Thanks for the patches. They look very good to me. Just two nits below. I can do the small updates on commit if there would be no other changes. But I'd like to get some review from audit guys for patch 3/3 before I commit this. > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index caa1211bac8c..cf3584351e00 100644 > --- a/fs/notify/fanotify/fanotify_user.c > +++ b/fs/notify/fanotify/fanotify_user.c > @@ -283,19 +283,44 @@ static int create_fd(struct fsnotify_group *group, const struct path *path, > return client_fd; > } > > +static int process_access_response_info(int fd, const char __user *info, size_t info_len, > + struct fanotify_response_info_audit_rule *friar) I prefer to keep lines within 80 columns, unless there is really good reason (like with strings) to have them longer. BTW, why do you call the info structure 'friar'? I feel some language twist escapes me ;) > +{ > + if (fd == FAN_NOFD) > + return -ENOENT; I would not test 'fd' in this function at all. After all it is not part of the response info structure and you do check it in process_access_response() anyway. > + > + if (info_len != sizeof(*friar)) > + return -EINVAL; > + > + if (copy_from_user(friar, info, sizeof(*friar))) > + return -EFAULT; > + > + if (friar->hdr.type != FAN_RESPONSE_INFO_AUDIT_RULE) > + return -EINVAL; > + if (friar->hdr.pad != 0) > + return -EINVAL; > + if (friar->hdr.len != sizeof(*friar)) > + return -EINVAL; > + > + return info_len; > +} > + ... > @@ -327,10 +359,18 @@ static int process_access_response(struct fsnotify_group *group, > return -EINVAL; > } > > - if (fd < 0) > + if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT)) > return -EINVAL; > > - if ((response & FAN_AUDIT) && !FAN_GROUP_FLAG(group, FAN_ENABLE_AUDIT)) > + if (response & FAN_INFO) { > + ret = process_access_response_info(fd, info, info_len, &friar); > + if (ret < 0) > + return ret; > + } else { > + ret = 0; > + } > + > + if (fd < 0) > return -EINVAL; And here I'd do: if (fd == FAN_NOFD) return 0; if (fd < 0) return -EINVAL; As we talked in previous revisions we'd specialcase FAN_NOFD to just verify extra info is understood by the kernel so that application writing fanotify responses has a way to check which information it can provide to the kernel. Honza -- Jan Kara SUSE Labs, CR