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    SubjectRe: [PATCH v9 16/23] ima: Implement ima_free_policy_rules() for freeing of an ima_namespace
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    Hi Stefan,

    On Tue, 2022-01-25 at 17:46 -0500, Stefan Berger wrote:
    > From: Stefan Berger <stefanb@linux.ibm.com>
    >
    > Implement ima_free_policy_rules() that is needed when an ima_namespace
    > is freed.
    >
    > Only reset temp_ima_appraise when using init_ima_ns.

    Instead of having to walk the policy rules to know if there are any
    "appraise" rules, the ima_appraise flag is set. For now, only reset
    temp_ima_appraise flag on failed policy rule updates for init_ima_ns.

    >
    > Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
    >
    > ---
    > v9:
    > - Only reset temp_ima_appraise when using init_ima_ns.
    > ---
    > security/integrity/ima/ima.h | 1 +
    > security/integrity/ima/ima_policy.c | 20 +++++++++++++++++++-
    > 2 files changed, 20 insertions(+), 1 deletion(-)
    >
    > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
    > index aea8fb8d2854..8c757223d549 100644
    > --- a/security/integrity/ima/ima.h
    > +++ b/security/integrity/ima/ima.h
    > @@ -329,6 +329,7 @@ void ima_update_policy_flags(struct ima_namespace *ns);
    > ssize_t ima_parse_add_rule(struct ima_namespace *ns, char *rule);
    > void ima_delete_rules(struct ima_namespace *ns);
    > int ima_check_policy(struct ima_namespace *ns);
    > +void ima_free_policy_rules(struct ima_namespace *ns);
    > void *ima_policy_start(struct seq_file *m, loff_t *pos);
    > void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos);
    > void ima_policy_stop(struct seq_file *m, void *v);
    > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
    > index e8140e73d80b..47f2d1b5d156 100644
    > --- a/security/integrity/ima/ima_policy.c
    > +++ b/security/integrity/ima/ima_policy.c
    > @@ -1880,13 +1880,31 @@ void ima_delete_rules(struct ima_namespace *ns)
    > {
    > struct ima_rule_entry *entry, *tmp;
    >
    > - temp_ima_appraise = 0;
    > + if (ns == &init_ima_ns)
    > + temp_ima_appraise = 0;
    > +
    > list_for_each_entry_safe(entry, tmp, &ns->ima_temp_rules, list) {
    > list_del(&entry->list);
    > ima_free_rule(entry);
    > }
    > }
    >
    > +/**
    > + * ima_free_policy_rules - free all policy rules
    > + * @ns: IMA namespace that has the policy
    > + */
    > +void ima_free_policy_rules(struct ima_namespace *ns)
    > +{
    > + struct ima_rule_entry *entry, *tmp;
    > +
    > + ima_delete_rules(ns);

    When the IMA policy is being extended, new rules are temporarily added
    to the ima_temp_rules list. If the entire set of rules being added are
    valid, they're appended to the tail.

    There shouldn't be any rules on the ima_temp_rules list unless the
    policy is currently being extended. Is that possible at this point?

    > +
    > + list_for_each_entry_safe(entry, tmp, &ns->ima_policy_rules, list) {
    > + list_del(&entry->list);
    > + ima_free_rule(entry);
    > + }
    > +}
    > +
    > #define __ima_hook_stringify(func, str) (#func),
    >
    > const char *const func_tokens[] = {

    thanks,

    Mimi

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