From dcf49dbc8077e278ddd1bc7298abc781496e8a08 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 26 Jun 2019 21:02:32 +0100 Subject: [PATCH] keys: Add a 'recurse' flag for keyring searches 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 --- 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 a0e245f..ae930ae 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 3a507b9..181cb7f 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 69a0788..084027e 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 fb2debc..ff10273 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 3b0a579..3782af4 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 c4479af..2cfc712 100644 --- a/net/rxrpc/security.c +++ b/net/rxrpc/security.c @@ -148,7 +148,7 @@ found_service: /* 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 9908087..358f614 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 4305414..aa36129 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 9f418e6..169409b 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 a5ee3b4..20891cd 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -685,6 +685,9 @@ descend_to_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 f081dce..b4f5ba5 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 f8ffb06..b07f768 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 36c55ef..1ffd380 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 99ed7a8..f613987 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; -- 2.7.4