apparmor: switch from profiles to using labels on contexts

Begin the actual switch to using domain labels by storing them on
the context and converting the label to a singular profile where
possible.

Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen 2017-06-09 08:14:28 -07:00
parent f1bd904175
commit 637f688dc3
20 changed files with 686 additions and 529 deletions

View file

@ -246,6 +246,32 @@ void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
audit_log_format(ab, "\"");
}
/**
* aa_audit_perms_cb - generic callback fn for auditing perms
* @ab: audit buffer (NOT NULL)
* @va: audit struct to audit values of (NOT NULL)
*/
static void aa_audit_perms_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
if (aad(sa)->request) {
audit_log_format(ab, " requested_mask=");
aa_audit_perm_mask(ab, aad(sa)->request, aa_file_perm_chrs,
PERMS_CHRS_MASK, aa_file_perm_names,
PERMS_NAMES_MASK);
}
if (aad(sa)->denied) {
audit_log_format(ab, "denied_mask=");
aa_audit_perm_mask(ab, aad(sa)->denied, aa_file_perm_chrs,
PERMS_CHRS_MASK, aa_file_perm_names,
PERMS_NAMES_MASK);
}
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
FLAGS_NONE, GFP_ATOMIC);
}
/**
* aa_apply_modes_to_perms - apply namespace and profile flags to perms
* @profile: that perms where computed from
@ -309,6 +335,143 @@ void aa_compute_perms(struct aa_dfa *dfa, unsigned int state,
// perms->xindex = dfa_user_xindex(dfa, state);
}
/**
* aa_perms_accum_raw - accumulate perms with out masking off overlapping perms
* @accum - perms struct to accumulate into
* @addend - perms struct to add to @accum
*/
void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend)
{
accum->deny |= addend->deny;
accum->allow &= addend->allow & ~addend->deny;
accum->audit |= addend->audit & addend->allow;
accum->quiet &= addend->quiet & ~addend->allow;
accum->kill |= addend->kill & ~addend->allow;
accum->stop |= addend->stop & ~addend->allow;
accum->complain |= addend->complain & ~addend->allow & ~addend->deny;
accum->cond |= addend->cond & ~addend->allow & ~addend->deny;
accum->hide &= addend->hide & ~addend->allow;
accum->prompt |= addend->prompt & ~addend->allow & ~addend->deny;
}
/**
* aa_perms_accum - accumulate perms, masking off overlapping perms
* @accum - perms struct to accumulate into
* @addend - perms struct to add to @accum
*/
void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend)
{
accum->deny |= addend->deny;
accum->allow &= addend->allow & ~accum->deny;
accum->audit |= addend->audit & accum->allow;
accum->quiet &= addend->quiet & ~accum->allow;
accum->kill |= addend->kill & ~accum->allow;
accum->stop |= addend->stop & ~accum->allow;
accum->complain |= addend->complain & ~accum->allow & ~accum->deny;
accum->cond |= addend->cond & ~accum->allow & ~accum->deny;
accum->hide &= addend->hide & ~accum->allow;
accum->prompt |= addend->prompt & ~accum->allow & ~accum->deny;
}
void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label,
int type, u32 request, struct aa_perms *perms)
{
/* TODO: doesn't yet handle extended types */
unsigned int state;
state = aa_dfa_next(profile->policy.dfa,
profile->policy.start[AA_CLASS_LABEL],
type);
aa_label_match(profile, label, state, false, request, perms);
}
/* currently unused */
int aa_profile_label_perm(struct aa_profile *profile, struct aa_profile *target,
u32 request, int type, u32 *deny,
struct common_audit_data *sa)
{
struct aa_perms perms;
aad(sa)->label = &profile->label;
aad(sa)->peer = &target->label;
aad(sa)->request = request;
aa_profile_match_label(profile, &target->label, type, request, &perms);
aa_apply_modes_to_perms(profile, &perms);
*deny |= request & perms.deny;
return aa_check_perms(profile, &perms, request, sa, aa_audit_perms_cb);
}
/**
* aa_check_perms - do audit mode selection based on perms set
* @profile: profile being checked
* @perms: perms computed for the request
* @request: requested perms
* @deny: Returns: explicit deny set
* @sa: initialized audit structure (MAY BE NULL if not auditing)
* @cb: callback fn for tpye specific fields (MAY BE NULL)
*
* Returns: 0 if permission else error code
*
* Note: profile audit modes need to be set before calling by setting the
* perm masks appropriately.
*
* If not auditing then complain mode is not enabled and the
* error code will indicate whether there was an explicit deny
* with a positive value.
*/
int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms,
u32 request, struct common_audit_data *sa,
void (*cb)(struct audit_buffer *, void *))
{
int type, error;
bool stop = false;
u32 denied = request & (~perms->allow | perms->deny);
if (likely(!denied)) {
/* mask off perms that are not being force audited */
request &= perms->audit;
if (!request || !sa)
return 0;
type = AUDIT_APPARMOR_AUDIT;
error = 0;
} else {
error = -EACCES;
if (denied & perms->kill)
type = AUDIT_APPARMOR_KILL;
else if (denied == (denied & perms->complain))
type = AUDIT_APPARMOR_ALLOWED;
else
type = AUDIT_APPARMOR_DENIED;
if (denied & perms->stop)
stop = true;
if (denied == (denied & perms->hide))
error = -ENOENT;
denied &= ~perms->quiet;
if (!sa || !denied)
return error;
}
if (sa) {
aad(sa)->label = &profile->label;
aad(sa)->request = request;
aad(sa)->denied = denied;
aad(sa)->error = error;
aa_audit_msg(type, sa, cb);
}
if (type == AUDIT_APPARMOR_ALLOWED)
error = 0;
return error;
}
/**
* aa_policy_init - initialize a policy structure
* @policy: policy to initialize (NOT NULL)