[patch] iwmc3200wifi: add a range check to iwm_cfg80211_get_key()

[patch] iwmc3200wifi: add a range check to iwm_cfg80211_get_key()

[Dan Carpenter]

Smatch complains that "key_index" is capped at 5 in nl80211_get_key()
but iwm->keys[] only has 4 elements.  I don't know if this is really
needed, but the other ->get_key() implementations seemed to check
for overflows so I've added a check here.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/wireless/iwmc3200wifi/cfg80211.c b/drivers/net/wireless/iwmc3200wifi/cfg80211.c
index ed57e44..c42be81 100644
--- a/drivers/net/wireless/iwmc3200wifi/cfg80211.c
+++ b/drivers/net/wireless/iwmc3200wifi/cfg80211.c
@@ -187,13 +187,17 @@ static int iwm_cfg80211_get_key(struct wiphy *wiphy, struct net_device *ndev,
 						 struct key_params*))
 {
 	struct iwm_priv *iwm = ndev_to_iwm(ndev);
-	struct iwm_key *key = &iwm->keys[key_index];
+	struct iwm_key *key;
 	struct key_params params;
 
 	IWM_DBG_WEXT(iwm, DBG, "Getting key %d\n", key_index);
 
+	if (key_index >= IWM_NUM_KEYS)
+		return -ENOENT;
+
 	memset(&params, 0, sizeof(params));
 
+	key = &iwm->keys[key_index];
 	params.cipher = key->cipher;
 	params.key_len = key->key_len;
 	params.seq_len = key->seq_len;

Re: [patch] iwmc3200wifi: add a range check to iwm_cfg80211_get_key()

[Samuel Ortiz]

Hi Dan,

On Wed, Oct 12, 2011 at 11:10:37AM +0300, Dan Carpenter wrote:
> Smatch complains that "key_index" is capped at 5 in nl80211_get_key()
> but iwm->keys[] only has 4 elements.  I don't know if this is really
> needed, but the other ->get_key() implementations seemed to check
> for overflows so I've added a check here.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>

Cheers.
Samuel.

-- 
Intel Open Source Technology Centre
http://oss.intel.com/
---------------------------------------------------------------------
Intel Corporation SAS (French simplified joint stock company)
Registered headquarters: "Les Montalets"- 2, rue de Paris, 
92196 Meudon Cedex, France
Registration Number:  302 456 199 R.C.S. NANTERRE
Capital: 4,572,000 Euros

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.

[patch] iwmc3200wifi: add some more range checks

[Dan Carpenter]

My previous patch added a check to get_key() but missed a couple
other places which need range checks.

The problem here is that wifi drivers have different numbers of keys.
The lower levels assume that they can have up to 4 default keys and
2 management keys but this driver only has the default keys so we
could go past the end of the ->keys[] array.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/wireless/iwmc3200wifi/cfg80211.c b/drivers/net/wireless/iwmc3200wifi/cfg80211.c
index ed57e44..e20a38d 100644
--- a/drivers/net/wireless/iwmc3200wifi/cfg80211.c
+++ b/drivers/net/wireless/iwmc3200wifi/cfg80211.c
@@ -165,11 +165,15 @@ static int iwm_cfg80211_add_key(struct wiphy *wiphy, struct net_device *ndev,
 				struct key_params *params)
 {
 	struct iwm_priv *iwm = ndev_to_iwm(ndev);
-	struct iwm_key *key = &iwm->keys[key_index];
+	struct iwm_key *key;
 	int ret;
 
 	IWM_DBG_WEXT(iwm, DBG, "Adding key for %pM\n", mac_addr);
 
+	if (key_index >= IWM_NUM_KEYS)
+		return -ENOENT;
+
+	key = &iwm->keys[key_index];
 	memset(key, 0, sizeof(struct iwm_key));
 	ret = iwm_key_init(key, key_index, mac_addr, params);
 	if (ret < 0) {
@@ -210,8 +214,12 @@ static int iwm_cfg80211_del_key(struct wiphy *wiphy, struct net_device *ndev,
 				u8 key_index, bool pairwise, const u8 *mac_addr)
 {
 	struct iwm_priv *iwm = ndev_to_iwm(ndev);
-	struct iwm_key *key = &iwm->keys[key_index];
+	struct iwm_key *key;
 
+	if (key_index >= IWM_NUM_KEYS)
+		return -ENOENT;
+
+	key = &iwm->keys[key_index];
 	if (!iwm->keys[key_index].key_len) {
 		IWM_DBG_WEXT(iwm, DBG, "Key %d not used\n", key_index);
 		return 0;
@@ -232,6 +240,9 @@ static int iwm_cfg80211_set_default_key(struct wiphy *wiphy,
 
 	IWM_DBG_WEXT(iwm, DBG, "Default key index is: %d\n", key_index);
 
+	if (key_index >= IWM_NUM_KEYS)
+		return -ENOENT;
+
 	if (!iwm->keys[key_index].key_len) {
 		IWM_ERR(iwm, "Key %d not used\n", key_index);
 		return -EINVAL;

Re: [patch] iwmc3200wifi: add some more range checks

[Samuel Ortiz]

Hi Dan,

On Tue, Oct 18, 2011 at 09:50:43AM +0300, Dan Carpenter wrote:
> My previous patch added a check to get_key() but missed a couple
> other places which need range checks.
> 
> The problem here is that wifi drivers have different numbers of keys.
> The lower levels assume that they can have up to 4 default keys and
> 2 management keys but this driver only has the default keys so we
> could go past the end of the ->keys[] array.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Acked-by: Samuel Ortiz <sameo@linux.intel.com>

Cheers,
Samuel.

-- 
Intel Open Source Technology Centre
http://oss.intel.com/
---------------------------------------------------------------------
Intel Corporation SAS (French simplified joint stock company)
Registered headquarters: "Les Montalets"- 2, rue de Paris, 
92196 Meudon Cedex, France
Registration Number:  302 456 199 R.C.S. NANTERRE
Capital: 4,572,000 Euros

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.