[PATCH 3/9] keys: Add a 'recurse' flag for keyring searches [ver #4]
From: David Howells
Date: Wed Jun 19 2019 - 12:11:45 EST
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@xxxxxxxxxx>
---
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 a0e245f9576f..ae930ae9d590 100644
--- a/Documentation/security/keys/core.rst
+++ b/Documentation/security/keys/core.rst
@@ -1162,11 +1162,13 @@ 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 fb2debcacea0..ff102731b3db 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -341,7 +341,8 @@ 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 recurse);
extern int keyring_add_key(struct key *keyring,
struct key *key);
diff --git a/lib/digsig.c b/lib/digsig.c
index 3b0a579bdcdf..3782af401c68 100644
--- a/lib/digsig.c
+++ b/lib/digsig.c
@@ -221,7 +221,7 @@ int digsig_verify(struct key *keyring, const char *sig, int siglen,
/* search in specific keyring */
key_ref_t kref;
kref = keyring_search(make_key_ref(keyring, 1UL),
- &key_type_user, name);
+ &key_type_user, name, true);
if (IS_ERR(kref))
key = ERR_CAST(kref);
else
diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
index c4479afe8ae7..2cfc7125bc41 100644
--- a/net/rxrpc/security.c
+++ b/net/rxrpc/security.c
@@ -148,7 +148,7 @@ int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
/* look through the service's keyring */
kref = keyring_search(make_key_ref(rx->securities, 1UL),
- &key_type_rxrpc_s, kdesc);
+ &key_type_rxrpc_s, kdesc, true);
if (IS_ERR(kref)) {
read_unlock(&local->services_lock);
_leave(" = %ld [search]", PTR_ERR(kref));
diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index 99080871eb9f..358f614811e8 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -39,7 +39,7 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
key_ref_t kref;
kref = keyring_search(make_key_ref(key, 1),
- &key_type_asymmetric, name);
+ &key_type_asymmetric, name, true);
if (!IS_ERR(kref)) {
pr_err("Key '%s' is in ima_blacklist_keyring\n", name);
return ERR_PTR(-EKEYREJECTED);
@@ -51,7 +51,7 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
key_ref_t kref;
kref = keyring_search(make_key_ref(keyring, 1),
- &key_type_asymmetric, name);
+ &key_type_asymmetric, name, true);
if (IS_ERR(kref))
key = ERR_CAST(kref);
else
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 4305414795ae..aa361299a3ec 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -127,6 +127,7 @@ struct keyring_search_context {
#define KEYRING_SEARCH_NO_CHECK_PERM 0x0008 /* Don't check permissions */
#define KEYRING_SEARCH_DETECT_TOO_DEEP 0x0010 /* Give an error on excessive depth */
#define KEYRING_SEARCH_SKIP_EXPIRED 0x0020 /* Ignore expired keys (intention to replace) */
+#define KEYRING_SEARCH_RECURSE 0x0040 /* Search child keyrings also */
int (*iterator)(const void *object, void *iterator_data);
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 9f418e66f067..169409b611b0 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -762,7 +762,7 @@ long keyctl_keyring_search(key_serial_t ringid,
}
/* do the search */
- key_ref = keyring_search(keyring_ref, ktype, description);
+ key_ref = keyring_search(keyring_ref, ktype, description, true);
if (IS_ERR(key_ref)) {
ret = PTR_ERR(key_ref);
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index a5ee3b4d2eb8..20891cd198f0 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -685,6 +685,9 @@ static bool search_nested_keyrings(struct key *keyring,
* Non-keyrings avoid the leftmost branch of the root entirely (root
* slots 1-15).
*/
+ if (!(ctx->flags & KEYRING_SEARCH_RECURSE))
+ goto not_this_keyring;
+
ptr = READ_ONCE(keyring->keys.root);
if (!ptr)
goto not_this_keyring;
@@ -885,13 +888,15 @@ key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
* @keyring: The root of the keyring tree to be searched.
* @type: The type of keyring we want to find.
* @description: The name of the keyring we want to find.
+ * @recurse: True to search the children of @keyring also
*
* As keyring_search_rcu() above, but using the current task's credentials and
* type's default matching function and preferred search method.
*/
key_ref_t keyring_search(key_ref_t keyring,
struct key_type *type,
- const char *description)
+ const char *description,
+ bool recurse)
{
struct keyring_search_context ctx = {
.index_key.type = type,
@@ -906,6 +911,8 @@ key_ref_t keyring_search(key_ref_t keyring,
key_ref_t key;
int ret;
+ if (recurse)
+ ctx.flags |= KEYRING_SEARCH_RECURSE;
if (type->match_preparse) {
ret = type->match_preparse(&ctx.match_data);
if (ret < 0)
@@ -1176,7 +1183,8 @@ static int keyring_detect_cycle(struct key *A, struct key *B)
.flags = (KEYRING_SEARCH_NO_STATE_CHECK |
KEYRING_SEARCH_NO_UPDATE_TIME |
KEYRING_SEARCH_NO_CHECK_PERM |
- KEYRING_SEARCH_DETECT_TOO_DEEP),
+ KEYRING_SEARCH_DETECT_TOO_DEEP |
+ KEYRING_SEARCH_RECURSE),
};
rcu_read_lock();
diff --git a/security/keys/proc.c b/security/keys/proc.c
index f081dceae3b9..b4f5ba56b9cb 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -170,7 +170,8 @@ static int proc_keys_show(struct seq_file *m, void *v)
.match_data.cmp = lookup_user_key_possessed,
.match_data.raw_data = key,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
- .flags = KEYRING_SEARCH_NO_STATE_CHECK,
+ .flags = (KEYRING_SEARCH_NO_STATE_CHECK |
+ KEYRING_SEARCH_RECURSE),
};
key_ref = make_key_ref(key, 0);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index f8ffb06d0297..b07f768d23dc 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -531,7 +531,8 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
struct keyring_search_context ctx = {
.match_data.cmp = lookup_user_key_possessed,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
- .flags = KEYRING_SEARCH_NO_STATE_CHECK,
+ .flags = (KEYRING_SEARCH_NO_STATE_CHECK |
+ KEYRING_SEARCH_RECURSE),
};
struct request_key_auth *rka;
struct key *key;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 36c55ef47b9e..1ffd3803ce29 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -569,7 +569,8 @@ struct key *request_key_and_link(struct key_type *type,
.match_data.raw_data = description,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
.flags = (KEYRING_SEARCH_DO_STATE_CHECK |
- KEYRING_SEARCH_SKIP_EXPIRED),
+ KEYRING_SEARCH_SKIP_EXPIRED |
+ KEYRING_SEARCH_RECURSE),
};
struct key *key;
key_ref_t key_ref;
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 99ed7a8a273d..f613987e8a63 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -252,7 +252,8 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id)
.match_data.cmp = key_default_cmp,
.match_data.raw_data = description,
.match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
- .flags = KEYRING_SEARCH_DO_STATE_CHECK,
+ .flags = (KEYRING_SEARCH_DO_STATE_CHECK |
+ KEYRING_SEARCH_RECURSE),
};
struct key *authkey;
key_ref_t authkey_ref;