diff --git a/include/linux/key.h b/include/linux/key.h index b2752c35f42c..994d52f00c13 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -171,6 +171,7 @@ struct key { #define KEY_FLAG_NEGATIVE 5 /* set if key is negative */ #define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */ #define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */ +#define KEY_FLAG_UID_KEYRING 11 /* set if key is a user or user session keyring */ /* the description string * - this is used to match a key against search criteria @@ -212,6 +213,7 @@ extern struct key *key_alloc(struct key_type *type, #define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */ #define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */ #define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */ +#define KEY_ALLOC_UID_KEYRING 0x0010 /* allocating a user or user session keyring */ extern void key_revoke(struct key *key); extern void key_invalidate(struct key *key); diff --git a/security/keys/internal.h b/security/keys/internal.h index d4f1468b9b50..ce6d4634a840 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -126,7 +126,7 @@ extern key_ref_t search_process_keyrings(struct key_type *type, key_match_func_t match, const struct cred *cred); -extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check); +extern struct key *find_keyring_by_name(const char *name, bool uid_keyring); extern int install_user_keyrings(void); extern int install_thread_keyring_to_cred(struct cred *); diff --git a/security/keys/key.c b/security/keys/key.c index 6373ff18b8ea..248c2e731375 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -299,6 +299,8 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; + if (flags & KEY_ALLOC_UID_KEYRING) + key->flags |= 1 << KEY_FLAG_UID_KEYRING; memset(&key->type_data, 0, sizeof(key->type_data)); diff --git a/security/keys/keyring.c b/security/keys/keyring.c index e7d2d72204c0..604091c9c57d 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -583,15 +583,15 @@ found: /* * Find a keyring with the specified name. * - * All named keyrings in the current user namespace are searched, provided they - * grant Search permission directly to the caller (unless this check is - * skipped). Keyrings whose usage points have reached zero or who have been - * revoked are skipped. + * Only keyrings that have nonzero refcount, are not revoked, and are owned by a + * user in the current user namespace are considered. If @uid_keyring is %true, + * the keyring additionally must have been allocated as a user or user session + * keyring; otherwise, it must grant Search permission directly to the caller. * * Returns a pointer to the keyring with the keyring's refcount having being * incremented on success. -ENOKEY is returned if a key could not be found. */ -struct key *find_keyring_by_name(const char *name, bool skip_perm_check) +struct key *find_keyring_by_name(const char *name, bool uid_keyring) { struct key *keyring; int bucket; @@ -619,10 +619,15 @@ struct key *find_keyring_by_name(const char *name, bool skip_perm_check) if (strcmp(keyring->description, name) != 0) continue; - if (!skip_perm_check && - key_permission(make_key_ref(keyring, 0), - KEY_SEARCH) < 0) - continue; + if (uid_keyring) { + if (!test_bit(KEY_FLAG_UID_KEYRING, + &keyring->flags)) + continue; + } else { + if (key_permission(make_key_ref(keyring, 0), + KEY_SEARCH) < 0) + continue; + } /* we've got a match but we might end up racing with * key_cleanup() if the keyring is currently 'dead' diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 7a5abb2b9d56..1c963ff89681 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -76,7 +76,9 @@ int install_user_keyrings(void) if (IS_ERR(uid_keyring)) { uid_keyring = keyring_alloc(buf, user->uid, INVALID_GID, cred, user_keyring_perm, - KEY_ALLOC_IN_QUOTA, NULL); + KEY_ALLOC_UID_KEYRING | + KEY_ALLOC_IN_QUOTA, + NULL); if (IS_ERR(uid_keyring)) { ret = PTR_ERR(uid_keyring); goto error; @@ -92,7 +94,9 @@ int install_user_keyrings(void) session_keyring = keyring_alloc(buf, user->uid, INVALID_GID, cred, user_keyring_perm, - KEY_ALLOC_IN_QUOTA, NULL); + KEY_ALLOC_UID_KEYRING | + KEY_ALLOC_IN_QUOTA, + NULL); if (IS_ERR(session_keyring)) { ret = PTR_ERR(session_keyring); goto error_release;