Several label helpers only read from their struct aa_label * arguments:
they compare labels, test subset relationships, or check the mediation
bitmask, all via direct field/index access. Mark those parameters
const struct aa_label * to document intent and let the compiler enforce
that the label is not modified.

The converted functions are:
  - label_mediates(), label_mediates_safe()
  - aa_label_cmp() (and its vec_cmp() helper)
  - __aa_label_next_not_in_set(), aa_label_is_subset(),
    aa_label_is_unconfined_subset()
  - __aa_subj_label_is_cached()
  - aa_label_next_confined(), aa_label_next_in_merge()

These all access the label through direct indexing or manual iterators
rather than the label_for_each()/fn_for_each() macros, which are not
const-correct and so gate the majority of the remaining label consumers
(the print, match, and permission-check paths) from being constified.

No functional change.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Assisted-by: Claude:claude-opus-4.8

A number of functions take a struct aa_profile * argument that is only
ever read from: they compute DFA matches or apply the profile's mode
flags without modifying the profile, taking a reference on it, or
touching its embedded label. Mark those parameters const struct
aa_profile * to document intent and let the compiler enforce it.

The converted functions are the permission "compute" path plus a few
pure readers:
  - aa_apply_modes_to_perms(), aa_profile_match_label()
  - AUDIT_MODE()
  - aa_label_match() and its match_component()/label_compound_match()/
    label_components_match() helpers (label.c)
  - match_component()/label_compound_match()/label_components_match()/
    label_match()/change_profile_perms()/aa_xattrs_match() (domain.c)
  - match_iface()/match_addr_iface()/match_addr_iface_label()/
    skb_match_to_sk()/skb_match_to_cmd() (af_inet.c)
  - aa_profile_capget(), path_flags(), profile_query_cb()

The remaining aa_profile * parameters cannot be made const: the audit
path stores &profile->label into the owned, refcounted
apparmor_audit_data.subj_label/peer fields, and the domain/lifecycle
paths take references on the profile's embedded label
(aa_get_label()/aa_get_newest_label()/aa_get_profile()) or write
profile fields.

No functional change.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Assisted-by: Claude:claude-opus-4.8

aa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE
is passed. If the components are all distinct no duplicates are dropped,
dups is 0 and the terminator goes to vec[n], so the caller has to provide
room for n + 1 entries.

aa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len,
gfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but
vec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES
it uses the local array of LOCAL_VEC_ENTRIES pointers, above that it
allocates exactly len pointers. The terminator therefore lands one entry
past the end of the local array when len is LOCAL_VEC_ENTRIES, and one
entry past the end of the allocation when len is larger.

len comes from the number of "//&" separated components in the label name
and label_count_strn_entries() does not bound it. An unprivileged task
reaches the parse by writing to /proc/self/attr/apparmor/current or through
lsm_set_self_attr(2), both of which go through do_setattr(), and the name
is parsed before the change_profile permission is checked.
The query_label() path behind the securityfs .access file, which is
mode 0666, performs no permission check at all. Every component has to
resolve to a loaded profile, so a system with policy loaded is required.

The other two VEC_FLAG_TERMINATE users work on a label vec that
aa_label_alloc() has already sized with "+ 1 for null terminator entry on
vec". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing
len + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of
the local array and into kzalloc().

Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

get_newest_label() will always return a refcount, on the profile it
returns. However there are cases where we only need the refcount
if the label is stale and get_newest_label() will return a different
label.

Optimize this by making the get/put happen conditionally, by keeping
a flag indicating if the get was performed and a put is needed.

Signed-off-by: John Johansen <john.johansen@canonical.com>

AppArmor was putting the reference to i_private data on its end after
removing the original entry from the file system. However the inode
can aand does live beyond that point and it is possible that some of
the fs call back functions will be invoked after the reference has
been put, which results in a race between freeing the data and
accessing it through the fs.

While the rawdata/loaddata is the most likely candidate to fail the
race, as it has the fewest references. If properly crafted it might be
possible to trigger a race for the other types stored in i_private.

Fix this by moving the put of i_private referenced data to the correct
place which is during inode eviction.

Fixes: c961ee5f21b20 ("apparmor: convert from securityfs to apparmorfs for policy ns files")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Maxime Bélair <maxime.belair@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

The set of rules on a profile is not dynamically extended, instead
if a new ruleset is needed a new version of the profile is created.
This allows us to use a vector of rules instead of a list, slightly
reducing memory usage and simplifying the code.

Signed-off-by: John Johansen <john.johansen@canonical.com>

When a unix socket is passed into a different confinement domain make
sure its cached mediation labeling is updated to correctly reflect
which domains are using the socket.

Fixes: c05e705812d1 ("apparmor: add fine grained af_unix mediation")
Signed-off-by: John Johansen <john.johansen@canonical.com>

In order to speed up the mediated check, precompute and store the
result as a bit per class type. This will not only allow us to
speed up the mediation check but is also a step to removing the
unconfined special cases as the unconfined check can be replaced
with the generic label_mediates() check.

Note: label check does not currently work for capabilities and resources
      which need to have their mediation updated first.

Signed-off-by: John Johansen <john.johansen@canonical.com>

The macros for label combination XXX_comb are no longer used and there
are no plans to use them so remove the dead code.

Signed-off-by: John Johansen <john.johansen@canonical.com>

In the macro definition of next_comb(), a parameter L1 is accepted,
but it is not used. Hence, it should be removed.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>