apparmor: move change_profile mediation to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen
Родитель
89dbf1962a
Коммит
e00b02bb6a
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@ -301,26 +301,6 @@ static int change_profile_perms(struct aa_profile *profile,
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return label_match(profile, target, stack, start, true, request, perms);
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}
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static struct aa_perms change_profile_perms_wrapper(struct aa_profile *profile,
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struct aa_profile *target,
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u32 request,
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unsigned int start)
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{
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struct aa_perms perms;
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if (profile_unconfined(profile)) {
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perms.allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC;
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perms.audit = perms.quiet = perms.kill = 0;
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return perms;
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}
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if (change_profile_perms(profile, &target->label, false, request,
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start, &perms))
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return nullperms;
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return perms;
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}
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/**
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* __attach_match_ - find an attachment match
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* @name - to match against (NOT NULL)
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@ -1140,6 +1120,39 @@ fail:
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}
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static int change_profile_perms_wrapper(const char *op, const char *name,
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struct aa_profile *profile,
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struct aa_label *target, bool stack,
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u32 request, struct aa_perms *perms)
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{
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const char *info = NULL;
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int error = 0;
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/*
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* Fail explicitly requested domain transitions when no_new_privs
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* and not unconfined OR the transition results in a stack on
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* the current label.
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* Stacking domain transitions and transitions from unconfined are
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* allowed even when no_new_privs is set because this aways results
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* in a reduction of permissions.
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*/
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if (task_no_new_privs(current) && !stack &&
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!profile_unconfined(profile) &&
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!aa_label_is_subset(target, &profile->label)) {
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info = "no new privs";
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error = -EPERM;
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}
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if (!error)
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error = change_profile_perms(profile, target, stack, request,
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profile->file.start, perms);
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if (error)
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error = aa_audit_file(profile, perms, op, request, name,
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NULL, target, GLOBAL_ROOT_UID, info,
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error);
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return error;
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}
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/**
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* aa_change_profile - perform a one-way profile transition
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@ -1157,12 +1170,14 @@ fail:
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*/
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int aa_change_profile(const char *fqname, int flags)
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{
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const struct cred *cred;
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struct aa_label *label;
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struct aa_profile *profile, *target = NULL;
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struct aa_label *label, *new = NULL, *target = NULL;
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struct aa_profile *profile;
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struct aa_perms perms = {};
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const char *info = NULL, *op;
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const char *info = NULL;
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const char *auditname = fqname; /* retain leading & if stack */
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bool stack = flags & AA_CHANGE_STACK;
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int error = 0;
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char *op;
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u32 request;
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if (!fqname || !*fqname) {
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@ -1172,76 +1187,116 @@ int aa_change_profile(const char *fqname, int flags)
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if (flags & AA_CHANGE_ONEXEC) {
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request = AA_MAY_ONEXEC;
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op = OP_CHANGE_ONEXEC;
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if (stack)
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op = OP_STACK_ONEXEC;
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else
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op = OP_CHANGE_ONEXEC;
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} else {
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request = AA_MAY_CHANGE_PROFILE;
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op = OP_CHANGE_PROFILE;
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if (stack)
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op = OP_STACK;
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else
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op = OP_CHANGE_PROFILE;
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}
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cred = get_current_cred();
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label = aa_get_newest_cred_label(cred);
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profile = labels_profile(label);
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label = aa_get_current_label();
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/*
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* Fail explicitly requested domain transitions if no_new_privs
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* and not unconfined.
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* Domain transitions from unconfined are allowed even when
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* no_new_privs is set because this aways results in a reduction
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* of permissions.
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*/
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if (task_no_new_privs(current) && !profile_unconfined(profile)) {
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put_cred(cred);
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return -EPERM;
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if (*fqname == '&') {
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stack = true;
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/* don't have label_parse() do stacking */
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fqname++;
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}
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target = aa_label_parse(label, fqname, GFP_KERNEL, true, false);
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if (IS_ERR(target)) {
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struct aa_profile *tprofile;
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target = aa_fqlookupn_profile(label, fqname, strlen(fqname));
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if (!target) {
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info = "profile not found";
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error = -ENOENT;
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info = "label not found";
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error = PTR_ERR(target);
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target = NULL;
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/*
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* TODO: fixme using labels_profile is not right - do profile
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* per complain profile
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*/
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if ((flags & AA_CHANGE_TEST) ||
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!COMPLAIN_MODE(profile))
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!COMPLAIN_MODE(labels_profile(label)))
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goto audit;
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/* released below */
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target = aa_new_null_profile(profile, false, fqname,
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GFP_KERNEL);
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if (!target) {
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tprofile = aa_new_null_profile(labels_profile(label), false,
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fqname, GFP_KERNEL);
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if (!tprofile) {
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info = "failed null profile create";
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error = -ENOMEM;
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goto audit;
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}
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target = &tprofile->label;
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goto check;
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}
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perms = change_profile_perms_wrapper(profile, target, request,
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profile->file.start);
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if (!(perms.allow & request)) {
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error = -EACCES;
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goto audit;
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}
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/*
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* self directed transitions only apply to current policy ns
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* TODO: currently requiring perms for stacking and straight change
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* stacking doesn't strictly need this. Determine how much
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* we want to loosen this restriction for stacking
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*
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* if (!stack) {
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*/
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error = fn_for_each_in_ns(label, profile,
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change_profile_perms_wrapper(op, auditname,
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profile, target, stack,
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request, &perms));
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if (error)
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/* auditing done in change_profile_perms_wrapper */
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goto out;
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/* } */
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check:
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/* check if tracing task is allowed to trace target domain */
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error = may_change_ptraced_domain(&target->label, &info);
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if (error) {
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info = "ptrace prevents transition";
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error = may_change_ptraced_domain(target, &info);
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if (error && !fn_for_each_in_ns(label, profile,
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COMPLAIN_MODE(profile)))
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goto audit;
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}
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/* TODO: add permission check to allow this
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* if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) {
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* info = "not a single threaded task";
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* error = -EACCES;
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* goto audit;
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* }
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*/
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if (flags & AA_CHANGE_TEST)
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goto audit;
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goto out;
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if (flags & AA_CHANGE_ONEXEC)
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error = aa_set_current_onexec(&target->label, 0);
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else
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error = aa_replace_current_label(&target->label);
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if (!(flags & AA_CHANGE_ONEXEC)) {
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/* only transition profiles in the current ns */
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if (stack)
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new = aa_label_merge(label, target, GFP_KERNEL);
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else
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new = fn_label_build_in_ns(label, profile, GFP_KERNEL,
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aa_get_label(target),
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aa_get_label(&profile->label));
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if (IS_ERR_OR_NULL(new)) {
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info = "failed to build target label";
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error = PTR_ERR(new);
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new = NULL;
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perms.allow = 0;
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goto audit;
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}
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error = aa_replace_current_label(new);
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} else
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/* full transition will be built in exec path */
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error = aa_set_current_onexec(target, stack);
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audit:
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if (!(flags & AA_CHANGE_TEST))
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error = aa_audit_file(profile, &perms, op, request, NULL,
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fqname, NULL, GLOBAL_ROOT_UID, info,
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error);
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error = fn_for_each_in_ns(label, profile,
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aa_audit_file(profile, &perms, op, request, auditname,
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NULL, new ? new : target,
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GLOBAL_ROOT_UID, info, error));
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aa_put_profile(target);
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out:
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aa_put_label(new);
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aa_put_label(target);
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aa_put_label(label);
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put_cred(cred);
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return error;
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}
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