apparmor: make signal label match work when matching stacked labels
Given a label with a profile stack of
A//&B or A//&C ...
A ptrace rule should be able to specify a generic trace pattern with
a rule like
signal send A//&**,
however this is failing because while the correct label match routine
is called, it is being done post label decomposition so it is always
being done against a profile instead of the stacked label.
To fix this refactor the cross check to pass the full peer label in to
the label_match.
Signed-off-by: John Johansen <john.johansen@canonical.com>
diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
index 586facd..754f2ff 100644
--- a/security/apparmor/ipc.c
+++ b/security/apparmor/ipc.c
@@ -184,50 +184,34 @@ static void audit_signal_cb(struct audit_buffer *ab, void *va)
FLAGS_NONE, GFP_ATOMIC);
}
-/* TODO: update to handle compound name&name2, conditionals */
-static void profile_match_signal(struct aa_profile *profile, const char *label,
- int signal, struct aa_perms *perms)
-{
- unsigned int state;
-
- /* TODO: secondary cache check <profile, profile, perm> */
- state = aa_dfa_next(profile->policy.dfa,
- profile->policy.start[AA_CLASS_SIGNAL],
- signal);
- state = aa_dfa_match(profile->policy.dfa, state, label);
- aa_compute_perms(profile->policy.dfa, state, perms);
-}
-
static int profile_signal_perm(struct aa_profile *profile,
- struct aa_profile *peer, u32 request,
+ struct aa_label *peer, u32 request,
struct common_audit_data *sa)
{
struct aa_perms perms;
+ unsigned int state;
if (profile_unconfined(profile) ||
!PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
return 0;
- aad(sa)->peer = &peer->label;
- profile_match_signal(profile, peer->base.hname, aad(sa)->signal,
- &perms);
+ aad(sa)->peer = peer;
+ /* TODO: secondary cache check <profile, profile, perm> */
+ state = aa_dfa_next(profile->policy.dfa,
+ profile->policy.start[AA_CLASS_SIGNAL],
+ aad(sa)->signal);
+ aa_label_match(profile, peer, state, false, request, &perms);
aa_apply_modes_to_perms(profile, &perms);
return aa_check_perms(profile, &perms, request, sa, audit_signal_cb);
}
-static int aa_signal_cross_perm(struct aa_profile *sender,
- struct aa_profile *target,
- struct common_audit_data *sa)
-{
- return xcheck(profile_signal_perm(sender, target, MAY_WRITE, sa),
- profile_signal_perm(target, sender, MAY_READ, sa));
-}
-
int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
{
+ struct aa_profile *profile;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
aad(&sa)->signal = map_signal_num(sig);
- return xcheck_labels_profiles(sender, target, aa_signal_cross_perm,
- &sa);
+ return xcheck_labels(sender, target, profile,
+ profile_signal_perm(profile, target, MAY_WRITE, &sa),
+ profile_signal_perm(profile, sender, MAY_READ, &sa));
}
