diff --git a/Documentation/security/keys.txt b/Documentation/security/keys.txt
index 3849814bfe6dd22e501407b887e717fd4a8dc2fa..0e03baf271bdb00afa594770cd3bf170eab33160 100644
--- a/Documentation/security/keys.txt
+++ b/Documentation/security/keys.txt
@@ -1151,8 +1151,21 @@ access the data:
usage. This is called key->payload.rcu_data0. The following accessors
wrap the RCU calls to this element:
- rcu_assign_keypointer(struct key *key, void *data);
- void *rcu_dereference_key(struct key *key);
+ (a) Set or change the first payload pointer:
+
+ rcu_assign_keypointer(struct key *key, void *data);
+
+ (b) Read the first payload pointer with the key semaphore held:
+
+ [const] void *dereference_key_locked([const] struct key *key);
+
+ Note that the return value will inherit its constness from the key
+ parameter. Static analysis will give an error if it things the lock
+ isn't held.
+
+ (c) Read the first payload pointer with the RCU read lock held:
+
+ const void *dereference_key_rcu(const struct key *key);
===================
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 1cb2ca9dfae36d8df009aa9f68260ae7a071ba05..389a3637ffcc637c9a4540cec4db3b65a5cf773f 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1536,7 +1536,7 @@ static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string
down_read(&key->sem);
- ukp = user_key_payload(key);
+ ukp = user_key_payload_locked(key);
if (!ukp) {
up_read(&key->sem);
key_put(key);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 777ad9f4fc3c84acbb5d96878939c589341b7f86..8a3ecef30d3ce5b8e4b3a325ea147b457749a616 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2455,7 +2455,7 @@ cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
}
down_read(&key->sem);
- upayload = user_key_payload(key);
+ upayload = user_key_payload_locked(key);
if (IS_ERR_OR_NULL(upayload)) {
rc = upayload ? PTR_ERR(upayload) : -EINVAL;
goto out_key_put;
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 02eb6b9e44387d90daf6a35c03a052e7b855715d..d5d896fa5a71675272131d797919924b2398a85a 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -103,7 +103,7 @@ static int validate_user_key(struct fscrypt_info *crypt_info,
goto out;
}
down_read(&keyring_key->sem);
- ukp = user_key_payload(keyring_key);
+ ukp = user_key_payload_locked(keyring_key);
if (ukp->datalen != sizeof(struct fscrypt_key)) {
res = -EINVAL;
up_read(&keyring_key->sem);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 599a29237cfea5e401ac2ab225b48df080240a3b..95c1c8d3453922be63c7c0d13e2bd8acd18d7e12 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -117,7 +117,7 @@ ecryptfs_get_key_payload_data(struct key *key)
auth_tok = ecryptfs_get_encrypted_key_payload_data(key);
if (!auth_tok)
- return (struct ecryptfs_auth_tok *)user_key_payload(key)->data;
+ return (struct ecryptfs_auth_tok *)user_key_payload_locked(key)->data;
else
return auth_tok;
}
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
index 5d5ddaa84b215fd79956db4dac8292c374ee72ed..67f940892ef810dca6710a7f7c14dc2acd9b2619 100644
--- a/fs/fscache/object-list.c
+++ b/fs/fscache/object-list.c
@@ -329,7 +329,7 @@ static void fscache_objlist_config(struct fscache_objlist_data *data)
config = 0;
rcu_read_lock();
- confkey = user_key_payload(key);
+ confkey = user_key_payload_rcu(key);
buf = confkey->data;
for (len = confkey->datalen - 1; len >= 0; len--) {
diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
index c444285bb1b1698a985c1dd155ec83e12eb1cdd8..835c163f61af5324c988d1c38e51bfeb47983e76 100644
--- a/fs/nfs/nfs4idmap.c
+++ b/fs/nfs/nfs4idmap.c
@@ -316,7 +316,7 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
if (ret < 0)
goto out_up;
- payload = user_key_payload(rkey);
+ payload = user_key_payload_rcu(rkey);
if (IS_ERR_OR_NULL(payload)) {
ret = PTR_ERR(payload);
goto out_up;
diff --git a/include/keys/user-type.h b/include/keys/user-type.h
index c56fef40f53efa474a57303f46f773863e2fa4b9..e098cbe27db5462f155a3a9c64169d3c68a549c5 100644
--- a/include/keys/user-type.h
+++ b/include/keys/user-type.h
@@ -48,9 +48,14 @@ extern void user_describe(const struct key *user, struct seq_file *m);
extern long user_read(const struct key *key,
char __user *buffer, size_t buflen);
-static inline const struct user_key_payload *user_key_payload(const struct key *key)
+static inline const struct user_key_payload *user_key_payload_rcu(const struct key *key)
{
- return (struct user_key_payload *)rcu_dereference_key(key);
+ return (struct user_key_payload *)dereference_key_rcu(key);
+}
+
+static inline struct user_key_payload *user_key_payload_locked(const struct key *key)
+{
+ return (struct user_key_payload *)dereference_key_locked((struct key *)key);
}
#endif /* CONFIG_KEYS */
diff --git a/include/linux/key.h b/include/linux/key.h
index 722914798f3749c126c16620eb97411541dd8b9e..e45212f2777e36f531efe35ad7d56fcf67105c0b 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -354,7 +354,10 @@ static inline bool key_is_instantiated(const struct key *key)
!test_bit(KEY_FLAG_NEGATIVE, &key->flags);
}
-#define rcu_dereference_key(KEY) \
+#define dereference_key_rcu(KEY) \
+ (rcu_dereference((KEY)->payload.rcu_data0))
+
+#define dereference_key_locked(KEY) \
(rcu_dereference_protected((KEY)->payload.rcu_data0, \
rwsem_is_locked(&((struct key *)(KEY))->sem)))
diff --git a/lib/digsig.c b/lib/digsig.c
index 55b8b2f41a9e0a53acee9afb1353d70b6b899a8c..03d7c63837aecb36f74037212e9e7dd421e2e4c9 100644
--- a/lib/digsig.c
+++ b/lib/digsig.c
@@ -85,7 +85,7 @@ static int digsig_verify_rsa(struct key *key,
struct pubkey_hdr *pkh;
down_read(&key->sem);
- ukp = user_key_payload(key);
+ ukp = user_key_payload_locked(key);
if (ukp->datalen < sizeof(*pkh))
goto err1;
diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index ecc28cff08ab8110a9d96d6f7abe690ca77e9962..d502c94b1a82bb463bf1a224e69d2d187dfa53fc 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -70,7 +70,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
const char *options, char **_result, time64_t *_expiry)
{
struct key *rkey;
- const struct user_key_payload *upayload;
+ struct user_key_payload *upayload;
const struct cred *saved_cred;
size_t typelen, desclen;
char *desc, *cp;
@@ -141,7 +141,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
if (ret)
goto put;
- upayload = user_key_payload(rkey);
+ upayload = user_key_payload_locked(rkey);
len = upayload->datalen;
ret = -ENOMEM;
diff --git a/security/keys/dh.c b/security/keys/dh.c
index 531ed2ec132f4f0ab97143b86b3bb55d7eb527c8..893af4c450382ae45085d9efbfb1f3134a1b9479 100644
--- a/security/keys/dh.c
+++ b/security/keys/dh.c
@@ -55,7 +55,7 @@ static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
if (status == 0) {
const struct user_key_payload *payload;
- payload = user_key_payload(key);
+ payload = user_key_payload_locked(key);
if (maxlen == 0) {
*mpi = NULL;
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 4fb315cddf5b009672c3aeb31877135551125802..0010955d7876c2302704020af8b2ffb6010f2c0a 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -314,7 +314,7 @@ static struct key *request_user_key(const char *master_desc, const u8 **master_k
goto error;
down_read(&ukey->sem);
- upayload = user_key_payload(ukey);
+ upayload = user_key_payload_locked(ukey);
*master_key = upayload->data;
*master_keylen = upayload->datalen;
error:
@@ -926,7 +926,7 @@ static long encrypted_read(const struct key *key, char __user *buffer,
size_t asciiblob_len;
int ret;
- epayload = rcu_dereference_key(key);
+ epayload = dereference_key_locked(key);
/* returns the hex encoded iv, encrypted-data, and hmac as ascii */
asciiblob_len = epayload->datablob_len + ivsize + 1
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 90d61751ff12f3e9d4015900c39ac7b595411240..2ae31c5a87de9e9084de7e5f9350678da81b49a4 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -1140,12 +1140,12 @@ static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
static long trusted_read(const struct key *key, char __user *buffer,
size_t buflen)
{
- struct trusted_key_payload *p;
+ const struct trusted_key_payload *p;
char *ascii_buf;
char *bufp;
int i;
- p = rcu_dereference_key(key);
+ p = dereference_key_locked(key);
if (!p)
return -EINVAL;
if (!buffer || buflen <= 0)
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index e187c8909d9db1b306c194e94a25fbf7886adbb1..26605134f17a8a3cf7c7a5c0a0c14fd5a3052fcb 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -107,7 +107,7 @@ int user_update(struct key *key, struct key_preparsed_payload *prep)
/* attach the new data, displacing the old */
key->expiry = prep->expiry;
if (!test_bit(KEY_FLAG_NEGATIVE, &key->flags))
- zap = rcu_dereference_key(key);
+ zap = dereference_key_locked(key);
rcu_assign_keypointer(key, prep->payload.data[0]);
prep->payload.data[0] = NULL;
@@ -123,7 +123,7 @@ EXPORT_SYMBOL_GPL(user_update);
*/
void user_revoke(struct key *key)
{
- struct user_key_payload *upayload = key->payload.data[0];
+ struct user_key_payload *upayload = user_key_payload_locked(key);
/* clear the quota */
key_payload_reserve(key, 0);
@@ -169,7 +169,7 @@ long user_read(const struct key *key, char __user *buffer, size_t buflen)
const struct user_key_payload *upayload;
long ret;
- upayload = user_key_payload(key);
+ upayload = user_key_payload_locked(key);
ret = upayload->datalen;
/* we can return the data as is */