From 9b242610514fe387ef957bce05e1fdd3efd60359 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 26 Jun 2019 21:02:33 +0100 Subject: [PATCH] keys: Network namespace domain tag Create key domain tags for network namespaces and make it possible to automatically tag keys that are used by networked services (e.g. AF_RXRPC, AFS, DNS) with the default network namespace if not set by the caller. This allows keys with the same description but in different namespaces to coexist within a keyring. Signed-off-by: David Howells cc: netdev@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-afs@lists.infradead.org --- include/linux/key-type.h | 3 +++ include/net/net_namespace.h | 3 +++ net/core/net_namespace.c | 20 ++++++++++++++++++++ net/dns_resolver/dns_key.c | 1 + net/rxrpc/key.c | 2 ++ security/keys/keyring.c | 7 ++++++- 6 files changed, 35 insertions(+), 1 deletion(-) diff --git a/include/linux/key-type.h b/include/linux/key-type.h index e49d1de..2148a6b 100644 --- a/include/linux/key-type.h +++ b/include/linux/key-type.h @@ -74,6 +74,9 @@ struct key_type { */ size_t def_datalen; + unsigned int flags; +#define KEY_TYPE_NET_DOMAIN 0x00000001 /* Keys of this type have a net namespace domain */ + /* vet a description */ int (*vet_description)(const char *description); diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 12689dd..a56bf7f 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -71,6 +71,9 @@ struct net { */ struct llist_node cleanup_list; /* namespaces on death row */ +#ifdef CONFIG_KEYS + struct key_tag *key_domain; /* Key domain of operation tag */ +#endif struct user_namespace *user_ns; /* Owning user namespace */ struct ucounts *ucounts; spinlock_t nsid_lock; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 711b161..88e603b 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -38,9 +38,16 @@ EXPORT_SYMBOL_GPL(net_namespace_list); DECLARE_RWSEM(net_rwsem); EXPORT_SYMBOL_GPL(net_rwsem); +#ifdef CONFIG_KEYS +static struct key_tag init_net_key_domain = { .usage = REFCOUNT_INIT(1) }; +#endif + struct net init_net = { .count = REFCOUNT_INIT(1), .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), +#ifdef CONFIG_KEYS + .key_domain = &init_net_key_domain, +#endif }; EXPORT_SYMBOL(init_net); @@ -386,10 +393,22 @@ static struct net *net_alloc(void) if (!net) goto out_free; +#ifdef CONFIG_KEYS + net->key_domain = kzalloc(sizeof(struct key_tag), GFP_KERNEL); + if (!net->key_domain) + goto out_free_2; + refcount_set(&net->key_domain->usage, 1); +#endif + rcu_assign_pointer(net->gen, ng); out: return net; +#ifdef CONFIG_KEYS +out_free_2: + kmem_cache_free(net_cachep, net); + net = NULL; +#endif out_free: kfree(ng); goto out; @@ -566,6 +585,7 @@ static void cleanup_net(struct work_struct *work) list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) { list_del_init(&net->exit_list); dec_net_namespaces(net->ucounts); + key_remove_domain(net->key_domain); put_user_ns(net->user_ns); net_drop_ns(net); } diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c index a65d553..3e1a906 100644 --- a/net/dns_resolver/dns_key.c +++ b/net/dns_resolver/dns_key.c @@ -314,6 +314,7 @@ static long dns_resolver_read(const struct key *key, struct key_type key_type_dns_resolver = { .name = "dns_resolver", + .flags = KEY_TYPE_NET_DOMAIN, .preparse = dns_resolver_preparse, .free_preparse = dns_resolver_free_preparse, .instantiate = generic_key_instantiate, diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c index e7f6b88..2722189 100644 --- a/net/rxrpc/key.c +++ b/net/rxrpc/key.c @@ -43,6 +43,7 @@ static long rxrpc_read(const struct key *, char __user *, size_t); */ struct key_type key_type_rxrpc = { .name = "rxrpc", + .flags = KEY_TYPE_NET_DOMAIN, .preparse = rxrpc_preparse, .free_preparse = rxrpc_free_preparse, .instantiate = generic_key_instantiate, @@ -58,6 +59,7 @@ EXPORT_SYMBOL(key_type_rxrpc); */ struct key_type key_type_rxrpc_s = { .name = "rxrpc_s", + .flags = KEY_TYPE_NET_DOMAIN, .vet_description = rxrpc_vet_description_s, .preparse = rxrpc_preparse_s, .free_preparse = rxrpc_free_preparse_s, diff --git a/security/keys/keyring.c b/security/keys/keyring.c index d3c86fd..bca070f 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -17,10 +17,12 @@ #include #include #include +#include #include #include #include #include +#include #include "internal.h" /* @@ -220,7 +222,10 @@ void key_set_index_key(struct keyring_index_key *index_key) memcpy(index_key->desc, index_key->description, n); - index_key->domain_tag = &default_domain_tag; + if (index_key->type->flags & KEY_TYPE_NET_DOMAIN) + index_key->domain_tag = current->nsproxy->net_ns->key_domain; + else + index_key->domain_tag = &default_domain_tag; hash_key_type_and_desc(index_key); } -- 2.7.4