On Mon, 2023-07-24 at 09:44 -0400, Chuck Lever wrote: > On Mon, Jul 24, 2023 at 08:13:05AM -0400, Jeff Layton wrote: > > 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. > > > > 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 > > > > Reported-by: Ondrej Valousek <ondrej.valousek@xxxxxxxxxxx> > > Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2136452 > > Suggested-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > > --- > > Changes in v2: > > - always set missing ACEs whenever default ACL has any ACEs that are > > explicitly set. This better conforms to how setfacl works. > > - drop now-unneeded "empty" boolean > > - Link to v1: https://lore.kernel.org/r/20230719-nfsd-acl-v1-1-eb0faf3d2917@xxxxxxxxxx > > --- > > fs/nfsd/nfs4acl.c | 32 ++++++++++++++++++++++++++++---- > > 1 file changed, 28 insertions(+), 4 deletions(-) > > > > diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c > > index 518203821790..b931d4383517 100644 > > --- a/fs/nfsd/nfs4acl.c > > +++ b/fs/nfsd/nfs4acl.c > > @@ -441,7 +441,7 @@ struct posix_ace_state_array { > > * calculated so far: */ > > > > struct posix_acl_state { > > - int empty; > > + unsigned char valid; > > struct posix_ace_state owner; > > struct posix_ace_state group; > > struct posix_ace_state other; > > @@ -457,7 +457,6 @@ init_state(struct posix_acl_state *state, int cnt) > > int alloc; > > > > memset(state, 0, sizeof(struct posix_acl_state)); > > - state->empty = 1; > > /* > > * 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 > > @@ -500,7 +499,7 @@ posix_state_to_acl(struct posix_acl_state *state, unsigned int flags) > > * and effective cases: when there are no inheritable ACEs, > > * calls ->set_acl with a NULL ACL structure. > > */ > > - if (state->empty && (flags & NFS4_ACL_TYPE_DEFAULT)) > > + if (!state->valid && (flags & NFS4_ACL_TYPE_DEFAULT)) > > return NULL; > > > > /* > > @@ -622,9 +621,10 @@ static void process_one_v4_ace(struct posix_acl_state *state, > > struct nfs4_ace *ace) > > { > > u32 mask = ace->access_mask; > > + short type = ace2type(ace); > > int i; > > > > - state->empty = 0; > > + state->valid |= type; > > > > switch (ace2type(ace)) { > > Mechanical issue: the patch adds @type, but uses it just once. > The switch here also wants the value of ace2type(ace). > > Doh! I had that fixed in one version of the patch, but had to rework the branch and lost that delta. I can respin, or if you just want to fix that in place, then that would be fine too. > > case ACL_USER_OBJ: > > @@ -726,6 +726,30 @@ 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." > > + * > > + * Copy any missing ACEs from the effective set, if any ACEs were > > + * explicitly set. > > + */ > > + if (default_acl_state.valid) { > > + if (!(default_acl_state.valid & ACL_USER_OBJ)) > > + default_acl_state.owner = effective_acl_state.owner; > > + if (!(default_acl_state.valid & ACL_GROUP_OBJ)) > > + default_acl_state.group = effective_acl_state.group; > > + if (!(default_acl_state.valid & ACL_OTHER)) > > + 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: 7bfb36a2ee1d329a501ba4781db4145dc951c798 > > change-id: 20230719-nfsd-acl-5ab61537e4e6 > > > > Best regards, > > -- > > Jeff Layton <jlayton@xxxxxxxxxx> > > > -- Jeff Layton <jlayton@xxxxxxxxxx>
