Re: [PATCH] mac80211: Don't squash error codes in key setup functions

[Johannes Berg <johannes@sipsolutions.net>]

On Sun, 2010-08-01 at 17:37 +0100, Ben Hutchings wrote:
> 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.

Looks good to me.

Acked-by: Johannes Berg <johannes@sipsolutions.net>

> Reported-by: Marcin Owsiany <porridge@debian.org>
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
> ---
>  net/mac80211/aes_ccm.c  |    6 ++----
>  net/mac80211/aes_cmac.c |    6 ++----
>  net/mac80211/cfg.c      |    4 ++--
>  net/mac80211/key.c      |   14 ++++++++------
>  4 files changed, 14 insertions(+), 16 deletions(-)
> 
> diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c
> index a87cb3b..d2b03e0 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 3d097b3..b4d66cc 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 db4d934..34f32e3 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 50d1cff..acf97d6 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);
>  		}
>  	}
>