iwlwifi: prevent read outside array bounds

With EDCA and HCCA we have 16 potential tid values. This is accommodated by
mac80211, but iwlwifi only supports EDCA. With this implementation it is
thus possible for mac80211 to request a tid that will cause iwlwifi to read
outside array bounds. A similar problem exists if traffic is received in an
unsupported category.

We add error checking to catch these situations.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 21331552ff2..1bd7cd4dd80 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -332,6 +332,9 @@ static u8 rs_tl_add_packet(struct iwl_lq_sta *lq_data,
         } else
                 return MAX_TID_COUNT;
 
+        if (unlikely(tid >= TID_MAX_LOAD_COUNT))
+                return MAX_TID_COUNT;
+
         tl = &lq_data->load[tid];
 
         curr_time -= curr_time % TID_ROUND_VALUE;
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 9b76bd41f21..7686fc72eb8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -745,6 +745,8 @@ int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         if (ieee80211_is_data_qos(fc)) {
                 qc = ieee80211_get_qos_ctl(hdr);
                 tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
+                if (unlikely(tid >= MAX_TID_COUNT))
+                        goto drop_unlock;
                 seq_number = priv->stations[sta_id].tid[tid].seq_number;
                 seq_number &= IEEE80211_SCTL_SEQ;
                 hdr->seq_ctrl = hdr->seq_ctrl &
@@ -1238,6 +1240,9 @@ int iwl_tx_agg_stop(struct iwl_priv *priv , const u8 *ra, u16 tid)
                 return -EINVAL;
         }
 
+        if (unlikely(tid >= MAX_TID_COUNT))
+                return -EINVAL;
+
         if (likely(tid < ARRAY_SIZE(default_tid_to_tx_fifo)))
                 tx_fifo_id = default_tid_to_tx_fifo[tid];
         else
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index e617411d0c5..f339c5bd1fd 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -544,6 +544,8 @@ static int iwl3945_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         if (ieee80211_is_data_qos(fc)) {
                 qc = ieee80211_get_qos_ctl(hdr);
                 tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
+                if (unlikely(tid >= MAX_TID_COUNT))
+                        goto drop;
                 seq_number = priv->stations[sta_id].tid[tid].seq_number &
                                 IEEE80211_SCTL_SEQ;
                 hdr->seq_ctrl = cpu_to_le16(seq_number) |