9 files changed, 59 insertions, 29 deletions

diff --git a/include/linux/key.h b/include/linux/key.h
index b2bb01719561..ef19b99aff98 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -276,6 +276,19 @@ static inline key_serial_t key_serial(struct key *key)
         return key ? key->serial : 0;
 }
 
+/**
+ * key_is_instantiated - Determine if a key has been positively instantiated
+ * @key: The key to check.
+ *
+ * Return true if the specified key has been positively instantiated, false
+ * otherwise.
+ */
+static inline bool key_is_instantiated(const struct key *key)
+{
+        return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
+                !test_bit(KEY_FLAG_NEGATIVE, &key->flags);
+}
+
 #define rcu_dereference_key(KEY)                                        \
         (rcu_dereference_protected((KEY)->payload.rcudata,              \
                                    rwsem_is_locked(&((struct key *)(KEY))->sem)))
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index cfa7a5e1c5c9..fa000d26dc60 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -212,10 +212,12 @@ static void dns_resolver_describe(const struct key *key, struct seq_file *m)
         int err = key->type_data.x[0];
 
         seq_puts(m, key->description);
-        if (err)
-                seq_printf(m, ": %d", err);
-        else
-                seq_printf(m, ": %u", key->datalen);
+        if (key_is_instantiated(key)) {
+                if (err)
+                        seq_printf(m, ": %d", err);
+                else
+                        seq_printf(m, ": %u", key->datalen);
+        }
 }
 
 /*
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 07a025f81902..f375152a2500 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -109,11 +109,13 @@ extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
                                     const struct cred *cred,
                                     struct key_type *type,
                                     const void *description,
-                                    key_match_func_t match);
+                                    key_match_func_t match,
+                                    bool no_state_check);
 
 extern key_ref_t search_my_process_keyrings(struct key_type *type,
                                             const void *description,
                                             key_match_func_t match,
+                                            bool no_state_check,
                                             const struct cred *cred);
 extern key_ref_t search_process_keyrings(struct key_type *type,
                                          const void *description,
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index cdd2f3f88c88..a06ffab38568 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -176,13 +176,15 @@ static void keyring_describe(const struct key *keyring, struct seq_file *m)
         else
                 seq_puts(m, "[anon]");
 
-        rcu_read_lock();
-        klist = rcu_dereference(keyring->payload.subscriptions);
-        if (klist)
-                seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys);
-        else
-                seq_puts(m, ": empty");
-        rcu_read_unlock();
+        if (key_is_instantiated(keyring)) {
+                rcu_read_lock();
+                klist = rcu_dereference(keyring->payload.subscriptions);
+                if (klist)
+                        seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys);
+                else
+                        seq_puts(m, ": empty");
+                rcu_read_unlock();
+        }
 }
 
 /*
@@ -271,6 +273,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
  * @type: The type of key to search for.
  * @description: Parameter for @match.
  * @match: Function to rule on whether or not a key is the one required.
+ * @no_state_check: Don't check if a matching key is bad
  *
  * Search the supplied keyring tree for a key that matches the criteria given.
  * The root keyring and any linked keyrings must grant Search permission to the
@@ -303,7 +306,8 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
                              const struct cred *cred,
                              struct key_type *type,
                              const void *description,
-                             key_match_func_t match)
+                             key_match_func_t match,
+                             bool no_state_check)
 {
         struct {
                 struct keyring_list *keylist;
@@ -345,6 +349,8 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
         kflags = keyring->flags;
         if (keyring->type == type && match(keyring, description)) {
                 key = keyring;
+                if (no_state_check)
+                        goto found;
 
                 /* check it isn't negative and hasn't expired or been
                  * revoked */
@@ -384,11 +390,13 @@ descend:
                         continue;
 
                 /* skip revoked keys and expired keys */
-                if (kflags & (1 << KEY_FLAG_REVOKED))
-                        continue;
+                if (!no_state_check) {
+                        if (kflags & (1 << KEY_FLAG_REVOKED))
+                                continue;
 
-                if (key->expiry && now.tv_sec >= key->expiry)
-                        continue;
+                        if (key->expiry && now.tv_sec >= key->expiry)
+                                continue;
+                }
 
                 /* keys that don't match */
                 if (!match(key, description))
@@ -399,6 +407,9 @@ descend:
                                         cred, KEY_SEARCH) < 0)
                         continue;
 
+                if (no_state_check)
+                        goto found;
+
                 /* we set a different error code if we pass a negative key */
                 if (kflags & (1 << KEY_FLAG_NEGATIVE)) {
                         err = key->type_data.reject_error;
@@ -478,7 +489,7 @@ key_ref_t keyring_search(key_ref_t keyring,
                 return ERR_PTR(-ENOKEY);
 
         return keyring_search_aux(keyring, current->cred,
-                                  type, description, type->match);
+                                  type, description, type->match, false);
 }
 EXPORT_SYMBOL(keyring_search);
 
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 525cf8a29cdd..49bbc97943ad 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -199,7 +199,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
         if (key->perm & KEY_POS_VIEW) {
                 skey_ref = search_my_process_keyrings(key->type, key,
                                                       lookup_user_key_possessed,
-                                                      cred);
+                                                      true, cred);
                 if (!IS_ERR(skey_ref)) {
                         key_ref_put(skey_ref);
                         key_ref = make_key_ref(key, 1);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 930634e45149..6c0480db8885 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -331,6 +331,7 @@ void key_fsgid_changed(struct task_struct *tsk)
 key_ref_t search_my_process_keyrings(struct key_type *type,
                                      const void *description,
                                      key_match_func_t match,
+                                     bool no_state_check,
                                      const struct cred *cred)
 {
         key_ref_t key_ref, ret, err;
@@ -350,7 +351,7 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
         if (cred->thread_keyring) {
                 key_ref = keyring_search_aux(
                         make_key_ref(cred->thread_keyring, 1),
-                        cred, type, description, match);
+                        cred, type, description, match, no_state_check);
                 if (!IS_ERR(key_ref))
                         goto found;
 
@@ -371,7 +372,7 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
         if (cred->tgcred->process_keyring) {
                 key_ref = keyring_search_aux(
                         make_key_ref(cred->tgcred->process_keyring, 1),
-                        cred, type, description, match);
+                        cred, type, description, match, no_state_check);
                 if (!IS_ERR(key_ref))
                         goto found;
 
@@ -395,7 +396,7 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
                         make_key_ref(rcu_dereference(
                                              cred->tgcred->session_keyring),
                                      1),
-                        cred, type, description, match);
+                        cred, type, description, match, no_state_check);
                 rcu_read_unlock();
 
                 if (!IS_ERR(key_ref))
@@ -417,7 +418,7 @@ key_ref_t search_my_process_keyrings(struct key_type *type,
         else if (cred->user->session_keyring) {
                 key_ref = keyring_search_aux(
                         make_key_ref(cred->user->session_keyring, 1),
-                        cred, type, description, match);
+                        cred, type, description, match, no_state_check);
                 if (!IS_ERR(key_ref))
                         goto found;
 
@@ -459,7 +460,8 @@ key_ref_t search_process_keyrings(struct key_type *type,
 
         might_sleep();
 
-        key_ref = search_my_process_keyrings(type, description, match, cred);
+        key_ref = search_my_process_keyrings(type, description, match,
+                                             false, cred);
         if (!IS_ERR(key_ref))
                 goto found;
         err = key_ref;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index df3c0417ee40..b18a71745901 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -530,8 +530,7 @@ struct key *request_key_and_link(struct key_type *type,
                dest_keyring, flags);
 
         /* search all the process keyrings for a key */
-        key_ref = search_process_keyrings(type, description, type->match,
-                                          cred);
+        key_ref = search_process_keyrings(type, description, type->match, cred);
 
         if (!IS_ERR(key_ref)) {
                 key = key_ref_to_ptr(key_ref);
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 68164031a74e..f6337c9082eb 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -59,7 +59,8 @@ static void request_key_auth_describe(const struct key *key,
 
         seq_puts(m, "key:");
         seq_puts(m, key->description);
-        seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len);
+        if (key_is_instantiated(key))
+                seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len);
 }
 
 /*
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index c6ca8662a468..63bb1aaffc0a 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -169,8 +169,8 @@ EXPORT_SYMBOL_GPL(user_destroy);
 void user_describe(const struct key *key, struct seq_file *m)
 {
         seq_puts(m, key->description);
-
-        seq_printf(m, ": %u", key->datalen);
+        if (key_is_instantiated(key))
+                seq_printf(m, ": %u", key->datalen);
 }
 
 EXPORT_SYMBOL_GPL(user_describe);