Add a 'recurse' flag for keyring searches so that the flag can be omitted
and recursion disabled, thereby allowing just the nominated keyring to be
searched and none of the children.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 Documentation/security/keys/core.rst     |   10 ++++++----
 certs/blacklist.c                        |    2 +-
 crypto/asymmetric_keys/asymmetric_type.c |    2 +-
 include/linux/key.h                      |    3 ++-
 lib/digsig.c                             |    2 +-
 net/rxrpc/security.c                     |    2 +-
 security/integrity/digsig_asymmetric.c   |    4 ++--
 security/keys/internal.h                 |    1 +
 security/keys/keyctl.c                   |    2 +-
 security/keys/keyring.c                  |   12 ++++++++++--
 security/keys/proc.c                     |    3 ++-
 security/keys/process_keys.c             |    3 ++-
 security/keys/request_key.c              |    3 ++-
 security/keys/request_key_auth.c         |    3 ++-
 14 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/Documentation/security/keys/core.rst b/Documentation/security/keys/core.rst
index 9521c4207f01..99079b664036 100644
--- a/Documentation/security/keys/core.rst
+++ b/Documentation/security/keys/core.rst

@@ -1159,11 +1159,13 @@ payload contents" for more information.

        key_ref_t keyring_search(key_ref_t keyring_ref,
                                 const struct key_type *type,
-                                const char *description)
+                                const char *description,
+                                bool recurse)

-    This searches the keyring tree specified for a matching key. Error ENOKEY
-    is returned upon failure (use IS_ERR/PTR_ERR to determine). If successful,
-    the returned key will need to be released.
+    This searches the specified keyring only (recurse == false) or keyring tree
+    (recurse == true) specified for a matching key. Error ENOKEY is returned
+    upon failure (use IS_ERR/PTR_ERR to determine). If successful, the returned
+    key will need to be released.

     The possession attribute from the keyring reference is used to control
     access through the permissions mask and is propagated to the returned key

diff --git a/certs/blacklist.c b/certs/blacklist.c
index 3a507b9e2568..181cb7fa9540 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c

@@ -128,7 +128,7 @@ int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
        *p = 0;

        kref = keyring_search(make_key_ref(blacklist_keyring, true),
-                             &key_type_blacklist, buffer);
+                             &key_type_blacklist, buffer, false);
        if (!IS_ERR(kref)) {
                key_ref_put(kref);
                ret = -EKEYREJECTED;

diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 69a0788a7de5..084027ef3121 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c

@@ -87,7 +87,7 @@ struct key *find_asymmetric_key(struct key *keyring,
        pr_debug("Look up: \"%s\"\n", req);

        ref = keyring_search(make_key_ref(keyring, 1),
-                            &key_type_asymmetric, req);
+                            &key_type_asymmetric, req, true);
        if (IS_ERR(ref))
                pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref));
        kfree(req);

diff --git a/include/linux/key.h b/include/linux/key.h
index b39f5876b66d..bdd179169508 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h

@@ -333,7 +333,8 @@ extern int keyring_clear(struct key *keyring);

 extern key_ref_t keyring_search(key_ref_t keyring,
                                struct key_type *type,
-                               const char *description);
+                               const char *description,
+                               bool no_recurse);