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 5E247C001DE for ; Wed, 19 Jul 2023 21:22:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230392AbjGSVW2 (ORCPT ); Wed, 19 Jul 2023 17:22:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230383AbjGSVW1 (ORCPT ); Wed, 19 Jul 2023 17:22:27 -0400 Received: from mail-lj1-x229.google.com (mail-lj1-x229.google.com [IPv6:2a00:1450:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E1B71FD2; Wed, 19 Jul 2023 14:22:25 -0700 (PDT) Received: by mail-lj1-x229.google.com with SMTP id 38308e7fff4ca-2b702319893so984701fa.3; Wed, 19 Jul 2023 14:22:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1689801743; x=1692393743; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=pJlm+cK7svZ1+mHOBH75gskGJmblFGpUfmfoGmUCm8o=; b=VS+Uoeq0DWSXf7XqdrtJWwPfD3woLqRezpI2fCqDZOSP+XFOa+C8h2OX8JLqHv+VMn T9GZo+0vo/HihuA2LjQBQd+KU1iF1aDGHbie6gManZZJxAPX9Frxv/bG/2Zhc7vpJ8Eh pkXsbFYpAEfHPdsLsNsxJvBx2PxXId4bRKEzYtIBkn0N9d5fPKUk0YIhf6/nZL3efH0h SLxGuhlvmARirG4XJFcXF5Mj6rWub8StEuUuUTa/N5oOzctFDDz6rCX3CK93iGZPCQj8 PFxYLYPdADcJllOBFI5p0P+Qrzo/Ma5wDNJYk+Y3E6+6l9HB6szxBYvisvYWGJec8f1X 3ZYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689801743; x=1692393743; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=pJlm+cK7svZ1+mHOBH75gskGJmblFGpUfmfoGmUCm8o=; b=Mg6drLWLBWk3eyowwmQyVCMbD8Yr/mhHDEN7QQIsufqmJ2MsuoECRVVuu06AQ/9Wr2 chrKAe34ELh3lkyB54zHNQHW0XoGevjzeb5uMjhCLkWT7wusvp4E0n2zocj5qGdlkgUW D96ePLsFwKRlYo1DZBnC+7K+nB1LCNPviZaFwyW5lqa7zuxk8xnOhUYiCwFBo8pfdtO3 JwPU+ktNRUUTuHSHQyhtDoPNcBrFe7Vehp7J1iLhuyRP206YxpZW5C57PawTaSUKSx+7 jVYroX9agY5ThVJCWdcb97nKyB1qQ0PYKeRJXObJCvl7GUV+I0h1Z2DYS+ubbfMB1BFt p9Bw== X-Gm-Message-State: ABy/qLZKsP8MiCahNo8kX0HVNqPz6Oy4CgQE3Gap6W2R+dhWkOgFwspW brZMTWZfhLVAwdMnpALB4DzIIO8bjxKsz4xPuas= X-Google-Smtp-Source: APBJJlEte7wDHVx/7CCyhGbmcGxCBZKgA8C7oEisNnlOb1KnVNDN2HzYFr1LRSskWr1GmqvIAsATk8NKUz6F8o8MtdI= X-Received: by 2002:a2e:9643:0:b0:2b6:ec2a:a67e with SMTP id z3-20020a2e9643000000b002b6ec2aa67emr742682ljh.53.1689801743017; Wed, 19 Jul 2023 14:22:23 -0700 (PDT) MIME-Version: 1.0 References: <20230719-nfsd-acl-v1-1-eb0faf3d2917@kernel.org> In-Reply-To: <20230719-nfsd-acl-v1-1-eb0faf3d2917@kernel.org> From: =?UTF-8?Q?Andreas_Gr=C3=BCnbacher?= Date: Wed, 19 Jul 2023 23:22:11 +0200 Message-ID: Subject: Re: [PATCH] nfsd: inherit required unset default acls from effective set To: Jeff Layton Cc: Chuck Lever , Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey , linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Ondrej Valousek , Andreas Gruenbacher Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Hi Jeff, this patch seems useful, thanks. Am Mi., 19. Juli 2023 um 19:56 Uhr schrieb Jeff Layton : > A well-formed NFSv4 ACL will always contain OWNER@/GROUP@/EVERYONE@ > ACEs, but there is no requirement for inheritable entries for those > entities. POSIX ACLs must always have owner/group/other entries, even for a > default ACL. NFSv4 ACLs actually don't *need* to have OWNER@/GROUP@/EVERYONE@ entries; that's merely a result of translating POSIX ACLs (or file modes) to NFSv4 ACLs. > nfsd builds the default ACL from inheritable ACEs, but the current code > just leaves any unspecified ACEs zeroed out. The result is that adding a > default user or group ACE to an inode can leave it with unwanted deny > entries. > > For instance, a newly created directory with no acl will look something > like this: > > # NFSv4 translation by server > A::OWNER@:rwaDxtTcCy > A::GROUP@:rxtcy > A::EVERYONE@:rxtcy > > # POSIX ACL of underlying file > user::rwx > group::r-x > other::r-x > > ...if I then add new v4 ACE: > > nfs4_setfacl -a A:fd:1000:rwx /mnt/local/test > > ...I end up with a result like this today: > > user::rwx > user:1000:rwx > group::r-x > mask::rwx > other::r-x > default:user::--- > default:user:1000:rwx > default:group::--- > default:mask::rwx > default:other::--- > > A::OWNER@:rwaDxtTcCy > A::1000:rwaDxtcy > A::GROUP@:rxtcy > A::EVERYONE@:rxtcy > D:fdi:OWNER@:rwaDx > A:fdi:OWNER@:tTcCy > A:fdi:1000:rwaDxtcy > A:fdi:GROUP@:tcy > A:fdi:EVERYONE@:tcy > > ...which is not at all expected. Adding a single inheritable allow ACE > should not result in everyone else losing access. > > The setfacl command solves a silimar issue by copying owner/group/other > entries from the effective ACL when none of them are set: > > "If a Default ACL entry is created, and the Default ACL contains no > owner, owning group, or others entry, a copy of the ACL owner, > owning group, or others entry is added to the Default ACL. > > Having nfsd do the same provides a more sane result (with no deny ACEs > in the resulting set): > > user::rwx > user:1000:rwx > group::r-x > mask::rwx > other::r-x > default:user::rwx > default:user:1000:rwx > default:group::r-x > default:mask::rwx > default:other::r-x > > A::OWNER@:rwaDxtTcCy > A::1000:rwaDxtcy > A::GROUP@:rxtcy > A::EVERYONE@:rxtcy > A:fdi:OWNER@:rwaDxtTcCy > A:fdi:1000:rwaDxtcy > A:fdi:GROUP@:rxtcy > A:fdi:EVERYONE@:rxtcy This resulting NFSv4 ACL is still rather dull; we end up with an inherit-only entry for each effective entry. Those could all be combined, resulting in: A:fd:OWNER@:rwaDxtTcCy A:fd:1000:rwaDxtcy A:fd:GROUP@:rxtcy A:fd:EVERYONE@:rxtcy This will be the common case, so maybe matching entry pairs can either be recombined or not generated in the first place as a further improvement. > Link: https://bugzilla.redhat.com/show_bug.cgi?id=2136452 > Reported-by: Ondrej Valousek > Suggested-by: Andreas Gruenbacher > Signed-off-by: Jeff Layton > --- > fs/nfsd/nfs4acl.c | 32 +++++++++++++++++++++++++++++--- > 1 file changed, 29 insertions(+), 3 deletions(-) > > diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c > index 518203821790..64e45551d1b6 100644 > --- a/fs/nfsd/nfs4acl.c > +++ b/fs/nfsd/nfs4acl.c > @@ -441,7 +441,8 @@ struct posix_ace_state_array { > * calculated so far: */ > > struct posix_acl_state { > - int empty; > + bool empty; > + unsigned char valid; Hmm, "valid" is a bitmask here but it only matters whether it is zero. Shouldn't a bool be good enough? Also, this variable indicates whether special "who" values are present (and which), so the name "valid" probably isn't the best choice. > struct posix_ace_state owner; > struct posix_ace_state group; > struct posix_ace_state other; > @@ -457,7 +458,7 @@ init_state(struct posix_acl_state *state, int cnt) > int alloc; > > memset(state, 0, sizeof(struct posix_acl_state)); > - state->empty = 1; > + state->empty = true; > /* > * In the worst case, each individual acl could be for a distinct > * named user or group, but we don't know which, so we allocate > @@ -624,7 +625,7 @@ static void process_one_v4_ace(struct posix_acl_state *state, > u32 mask = ace->access_mask; > int i; > > - state->empty = 0; > + state->empty = false; > > switch (ace2type(ace)) { > case ACL_USER_OBJ: > @@ -633,6 +634,7 @@ static void process_one_v4_ace(struct posix_acl_state *state, > } else { > deny_bits(&state->owner, mask); > } > + state->valid |= ACL_USER_OBJ; > break; > case ACL_USER: > i = find_uid(state, ace->who_uid); > @@ -655,6 +657,7 @@ static void process_one_v4_ace(struct posix_acl_state *state, > deny_bits_array(state->users, mask); > deny_bits_array(state->groups, mask); > } > + state->valid |= ACL_GROUP_OBJ; > break; > case ACL_GROUP: > i = find_gid(state, ace->who_gid); > @@ -686,6 +689,7 @@ static void process_one_v4_ace(struct posix_acl_state *state, > deny_bits_array(state->users, mask); > deny_bits_array(state->groups, mask); > } > + state->valid |= ACL_OTHER; > } > } > > @@ -726,6 +730,28 @@ static int nfs4_acl_nfsv4_to_posix(struct nfs4_acl *acl, > if (!(ace->flag & NFS4_ACE_INHERIT_ONLY_ACE)) > process_one_v4_ace(&effective_acl_state, ace); > } > + > + /* > + * At this point, the default ACL may have zeroed-out entries for owner, > + * group and other. That usually results in a non-sensical resulting ACL > + * that denies all access except to any ACE that was explicitly added. > + * > + * The setfacl command solves a similar problem with this logic: > + * > + * "If a Default ACL entry is created, and the Default ACL contains > + * no owner, owning group, or others entry, a copy of the ACL > + * owner, owning group, or others entry is added to the Default ACL." > + * > + * If none of the requisite ACEs were set, and some explicit user or group > + * ACEs were, copy the requisite entries from the effective set. > + */ > + if (!default_acl_state.valid && > + (default_acl_state.users->n || default_acl_state.groups->n)) { > + default_acl_state.owner = effective_acl_state.owner; > + default_acl_state.group = effective_acl_state.group; > + default_acl_state.other = effective_acl_state.other; > + } > + > *pacl = posix_state_to_acl(&effective_acl_state, flags); > if (IS_ERR(*pacl)) { > ret = PTR_ERR(*pacl); > > --- > base-commit: 9d985ab8ed33176c3c0380b7de589ea2ae51a48d > change-id: 20230719-nfsd-acl-5ab61537e4e6 > > Best regards, > -- > Jeff Layton Thanks, Andreas