From ce94927fa4173fcc1eca27bdc65a140064c8f1e6 Mon Sep 17 00:00:00 2001 From: Georgia Garcia Date: Wed, 14 Oct 2026 19:08:21 -0300 Subject: [PATCH] apparmor: fix profile leak when a policy load fails The error paths of aa_replace_profiles() and aa_unpack() do not break the refcount cycle between label and proxy. They just aa_put_profile() the new profiles, which drops the label refcount from 2 to 1, and the proxy keeps the profile alive. Every failed atomic policy load (e.g. "profile can not be replaced", or a later profile in the blob failing to unpack) leaks every new profile in the set, along with its proxy, rules and its loaddata reference. The leak is usually not visible from userspace, because the raw_data directory for a failed load is not created, but it becomes visible when the blob is deduplicated onto an existing loaddata, which then keeps its policy/raw_data/ directory forever. Add aa_put_unpublished_profile(), which drops the profile's own proxy before putting the profile, and use it on those error paths. The proxy of an unpacked profile is always freshly allocated and not referenced by anything else before the profile is published, so putting it is safe. Fixes: 637f688dc3dc ("apparmor: switch from profiles to using labels on contexts") Cc: stable@vger.kernel.org Signed-off-by: Georgia Garcia Signed-off-by: John Johansen --- security/apparmor/include/policy.h | 20 ++++++++++++++++++++ security/apparmor/policy.c | 3 +++ security/apparmor/policy_unpack.c | 4 +++- 3 files changed, 26 insertions(+), 1 deletion(-) diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index 0dcbf8cf1029..bb851654cb80 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -436,6 +436,26 @@ static inline void aa_put_profile(struct aa_profile *p) kref_put(&p->label.count.count, aa_label_kref); } +/** + * aa_put_unpublished_profile - put a profile that was never made visible + * @p: profile (MAYBE NULL) + * + * A newly allocated profile and its proxy reference each other + * (proxy->label holds a label refcount). That cycle is normally broken + * when the profile is replaced or removed, which redirects the proxy. + * A profile that is discarded before being added to the policy tree + * never goes through either path, so break the cycle here, otherwise + * the profile, its proxy and its rawdata are leaked. + */ +static inline void aa_put_unpublished_profile(struct aa_profile *p) +{ + if (p && p->label.proxy) { + aa_put_proxy(p->label.proxy); + p->label.proxy = NULL; + } + aa_put_profile(p); +} + static inline int AUDIT_MODE(const struct aa_profile *profile) { if (aa_g_audit != AUDIT_NORMAL) diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index bfe969b86957..63f7821b4dff 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -1462,6 +1462,9 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, } list_for_each_entry_safe(ent, tmp, &lh, list) { list_del_init(&ent->list); + /* new was never added to the policy tree */ + aa_put_unpublished_profile(ent->new); + ent->new = NULL; aa_load_ent_free(ent); } diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 7ebffb4ff74f..35dfa3b451f3 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -1822,13 +1822,15 @@ int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, fail_profile: kfree(ns_name); - aa_put_profile(profile); + aa_put_unpublished_profile(profile); fail: if (compressed_data) kvfree(compressed_data); list_for_each_entry_safe(ent, tmp, lh, list) { list_del_init(&ent->list); + aa_put_unpublished_profile(ent->new); + ent->new = NULL; aa_load_ent_free(ent); }