1 files changed, 82 insertions, 32 deletions

diff --git a/security/keys/key.c b/security/keys/key.c
index 50d96d4e06f2..1d039af99f50 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -412,8 +412,7 @@ EXPORT_SYMBOL(key_payload_reserve);
  * key_construction_mutex.
  */
 static int __key_instantiate_and_link(struct key *key,
-                                      const void *data,
-                                      size_t datalen,
+                                      struct key_preparsed_payload *prep,
                                       struct key *keyring,
                                       struct key *authkey,
                                       unsigned long *_prealloc)
@@ -431,7 +430,7 @@ static int __key_instantiate_and_link(struct key *key,
         /* can't instantiate twice */
         if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
                 /* instantiate the key */
-                ret = key->type->instantiate(key, data, datalen);
+                ret = key->type->instantiate(key, prep);
 
                 if (ret == 0) {
                         /* mark the key as being instantiated */
@@ -482,22 +481,37 @@ int key_instantiate_and_link(struct key *key,
                              struct key *keyring,
                              struct key *authkey)
 {
+        struct key_preparsed_payload prep;
         unsigned long prealloc;
         int ret;
 
+        memset(&prep, 0, sizeof(prep));
+        prep.data = data;
+        prep.datalen = datalen;
+        prep.quotalen = key->type->def_datalen;
+        if (key->type->preparse) {
+                ret = key->type->preparse(&prep);
+                if (ret < 0)
+                        goto error;
+        }
+
         if (keyring) {
                 ret = __key_link_begin(keyring, key->type, key->description,
                                        &prealloc);
                 if (ret < 0)
-                        return ret;
+                        goto error_free_preparse;
         }
 
-        ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey,
+        ret = __key_instantiate_and_link(key, &prep, keyring, authkey,
                                          &prealloc);
 
         if (keyring)
                 __key_link_end(keyring, key->type, prealloc);
 
+error_free_preparse:
+        if (key->type->preparse)
+                key->type->free_preparse(&prep);
+error:
         return ret;
 }
 
@@ -706,7 +720,7 @@ void key_type_put(struct key_type *ktype)
  * if we get an error.
  */
 static inline key_ref_t __key_update(key_ref_t key_ref,
-                                     const void *payload, size_t plen)
+                                     struct key_preparsed_payload *prep)
 {
         struct key *key = key_ref_to_ptr(key_ref);
         int ret;
@@ -722,7 +736,7 @@ static inline key_ref_t __key_update(key_ref_t key_ref,
 
         down_write(&key->sem);
 
-        ret = key->type->update(key, payload, plen);
+        ret = key->type->update(key, prep);
         if (ret == 0)
                 /* updating a negative key instantiates it */
                 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
@@ -774,6 +788,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
                                unsigned long flags)
 {
         unsigned long prealloc;
+        struct key_preparsed_payload prep;
         const struct cred *cred = current_cred();
         struct key_type *ktype;
         struct key *keyring, *key = NULL;
@@ -789,8 +804,9 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
         }
 
         key_ref = ERR_PTR(-EINVAL);
-        if (!ktype->match || !ktype->instantiate)
-                goto error_2;
+        if (!ktype->match || !ktype->instantiate ||
+            (!description && !ktype->preparse))
+                goto error_put_type;
 
         keyring = key_ref_to_ptr(keyring_ref);
 
@@ -798,18 +814,37 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 
         key_ref = ERR_PTR(-ENOTDIR);
         if (keyring->type != &key_type_keyring)
-                goto error_2;
+                goto error_put_type;
+
+        memset(&prep, 0, sizeof(prep));
+        prep.data = payload;
+        prep.datalen = plen;
+        prep.quotalen = ktype->def_datalen;
+        if (ktype->preparse) {
+                ret = ktype->preparse(&prep);
+                if (ret < 0) {
+                        key_ref = ERR_PTR(ret);
+                        goto error_put_type;
+                }
+                if (!description)
+                        description = prep.description;
+                key_ref = ERR_PTR(-EINVAL);
+                if (!description)
+                        goto error_free_prep;
+        }
 
         ret = __key_link_begin(keyring, ktype, description, &prealloc);
-        if (ret < 0)
-                goto error_2;
+        if (ret < 0) {
+                key_ref = ERR_PTR(ret);
+                goto error_free_prep;
+        }
 
         /* if we're going to allocate a new key, we're going to have
          * to modify the keyring */
         ret = key_permission(keyring_ref, KEY_WRITE);
         if (ret < 0) {
                 key_ref = ERR_PTR(ret);
-                goto error_3;
+                goto error_link_end;
         }
 
         /* if it's possible to update this type of key, search for an existing
@@ -840,25 +875,27 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
                         perm, flags);
         if (IS_ERR(key)) {
                 key_ref = ERR_CAST(key);
-                goto error_3;
+                goto error_link_end;
         }
 
         /* instantiate it and link it into the target keyring */
-        ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL,
-                                         &prealloc);
+        ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &prealloc);
         if (ret < 0) {
                 key_put(key);
                 key_ref = ERR_PTR(ret);
-                goto error_3;
+                goto error_link_end;
         }
 
         key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
 
- error_3:
+error_link_end:
         __key_link_end(keyring, ktype, prealloc);
- error_2:
+error_free_prep:
+        if (ktype->preparse)
+                ktype->free_preparse(&prep);
+error_put_type:
         key_type_put(ktype);
- error:
+error:
         return key_ref;
 
  found_matching_key:
@@ -866,10 +903,9 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
          * - we can drop the locks first as we have the key pinned
          */
         __key_link_end(keyring, ktype, prealloc);
-        key_type_put(ktype);
 
-        key_ref = __key_update(key_ref, payload, plen);
-        goto error;
+        key_ref = __key_update(key_ref, &prep);
+        goto error_free_prep;
 }
 EXPORT_SYMBOL(key_create_or_update);
 
@@ -888,6 +924,7 @@ EXPORT_SYMBOL(key_create_or_update);
  */
 int key_update(key_ref_t key_ref, const void *payload, size_t plen)
 {
+        struct key_preparsed_payload prep;
         struct key *key = key_ref_to_ptr(key_ref);
         int ret;
 
@@ -900,18 +937,31 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen)
 
         /* attempt to update it if supported */
         ret = -EOPNOTSUPP;
-        if (key->type->update) {
-                down_write(&key->sem);
-
-                ret = key->type->update(key, payload, plen);
-                if (ret == 0)
-                        /* updating a negative key instantiates it */
-                        clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
+        if (!key->type->update)
+                goto error;
 
-                up_write(&key->sem);
+        memset(&prep, 0, sizeof(prep));
+        prep.data = payload;
+        prep.datalen = plen;
+        prep.quotalen = key->type->def_datalen;
+        if (key->type->preparse) {
+                ret = key->type->preparse(&prep);
+                if (ret < 0)
+                        goto error;
         }
 
- error:
+        down_write(&key->sem);
+
+        ret = key->type->update(key, &prep);
+        if (ret == 0)
+                /* updating a negative key instantiates it */
+                clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
+
+        up_write(&key->sem);
+
+        if (key->type->preparse)
+                key->type->free_preparse(&prep);
+error:
         return ret;
 }
 EXPORT_SYMBOL(key_update);