mac80211: Don't squash error codes in key setup functions

ieee80211_add_key() currently returns -ENOMEM in case of any error,
including a missing crypto algorithm.  Change ieee80211_key_alloc()
and ieee80211_aes_{key_setup_encrypt,cmac_key_setup}() to encode
errors with ERR_PTR() rather than returning NULL, and change
ieee80211_add_key() accordingly.

Compile-tested only.

Reported-by: Marcin Owsiany <porridge@debian.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 14 insertions, 16 deletions

diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c
index a87cb3ba2df6..d2b03e0851ef 100644
--- a/net/mac80211/aes_ccm.c
+++ b/net/mac80211/aes_ccm.c
@@ -138,10 +138,8 @@ struct crypto_cipher *ieee80211_aes_key_setup_encrypt(const u8 key[])
         struct crypto_cipher *tfm;
 
         tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(tfm))
-                return NULL;
-
-        crypto_cipher_setkey(tfm, key, ALG_CCMP_KEY_LEN);
+        if (!IS_ERR(tfm))
+                crypto_cipher_setkey(tfm, key, ALG_CCMP_KEY_LEN);
 
         return tfm;
 }
diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index 3d097b3d7b62..b4d66cca76d6 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -119,10 +119,8 @@ struct crypto_cipher * ieee80211_aes_cmac_key_setup(const u8 key[])
         struct crypto_cipher *tfm;
 
         tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(tfm))
-                return NULL;
-
-        crypto_cipher_setkey(tfm, key, AES_CMAC_KEY_LEN);
+        if (!IS_ERR(tfm))
+                crypto_cipher_setkey(tfm, key, AES_CMAC_KEY_LEN);
 
         return tfm;
 }
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 29ac8e1a509e..19c6146010b7 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -150,8 +150,8 @@ static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
 
         key = ieee80211_key_alloc(alg, key_idx, params->key_len, params->key,
                                   params->seq_len, params->seq);
-        if (!key)
-                return -ENOMEM;
+        if (IS_ERR(key))
+                return PTR_ERR(key);
 
         mutex_lock(&sdata->local->sta_mtx);
 
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 1b9d87ed143a..d6dbc8ea4ead 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -234,13 +234,13 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
                                           size_t seq_len, const u8 *seq)
 {
         struct ieee80211_key *key;
-        int i, j;
+        int i, j, err;
 
         BUG_ON(idx < 0 || idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS);
 
         key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
         if (!key)
-                return NULL;
+                return ERR_PTR(-ENOMEM);
 
         /*
          * Default to software encryption; we'll later upload the
@@ -296,9 +296,10 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
                  * it does not need to be initialized for every packet.
                  */
                 key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(key_data);
-                if (!key->u.ccmp.tfm) {
+                if (IS_ERR(key->u.ccmp.tfm)) {
+                        err = PTR_ERR(key->u.ccmp.tfm);
                         kfree(key);
-                        return NULL;
+                        key = ERR_PTR(err);
                 }
         }
 
@@ -309,9 +310,10 @@ struct ieee80211_key *ieee80211_key_alloc(enum ieee80211_key_alg alg,
                  */
                 key->u.aes_cmac.tfm =
                         ieee80211_aes_cmac_key_setup(key_data);
-                if (!key->u.aes_cmac.tfm) {
+                if (IS_ERR(key->u.aes_cmac.tfm)) {
+                        err = PTR_ERR(key->u.aes_cmac.tfm);
                         kfree(key);
-                        return NULL;
+                        key = ERR_PTR(err);
                 }
         }