ath6kl: add some bounds checking

The "ev->traffic_class" and "reply->ac" variables come from the network
and they're used as an offset into the wmi->stream_exist_for_ac[] array.
Those variables are u8 so they can be 0-255 but the stream_exist_for_ac[]
array only has WMM_NUM_AC (4) elements.  We need to add a couple bounds
checks to prevent array overflows.

I also modified one existing check from "if (traffic_class > 3) {" to
"if (traffic_class >= WMM_NUM_AC) {" just to make them all consistent.

Fixes: bdcd81707973 (" Add ath6kl cleaned up driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index 39925a8f5e85fc34807f1c24de1fed98f39b6bb1..2382c6c46851ee91fde89c408b5f4e4d0575e496 100644 (file)
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -1176,6 +1176,10 @@ static int ath6kl_wmi_pstream_timeout_event_rx(struct wmi *wmi, u8 *datap,
                return -EINVAL;
 
        ev = (struct wmi_pstream_timeout_event *) datap;
+       if (ev->traffic_class >= WMM_NUM_AC) {
+               ath6kl_err("invalid traffic class: %d\n", ev->traffic_class);
+               return -EINVAL;
+       }
 
        /*
         * When the pstream (fat pipe == AC) timesout, it means there were
@@ -1516,6 +1520,10 @@ static int ath6kl_wmi_cac_event_rx(struct wmi *wmi, u8 *datap, int len,
                return -EINVAL;
 
        reply = (struct wmi_cac_event *) datap;
+       if (reply->ac >= WMM_NUM_AC) {
+               ath6kl_err("invalid AC: %d\n", reply->ac);
+               return -EINVAL;
+       }
 
        if ((reply->cac_indication == CAC_INDICATION_ADMISSION_RESP) &&
            (reply->status_code != IEEE80211_TSPEC_STATUS_ADMISS_ACCEPTED)) {
@@ -2632,7 +2640,7 @@ int ath6kl_wmi_delete_pstream_cmd(struct wmi *wmi, u8 if_idx, u8 traffic_class,
        u16 active_tsids = 0;
        int ret;
 
-       if (traffic_class > 3) {
+       if (traffic_class >= WMM_NUM_AC) {
                ath6kl_err("invalid traffic class: %d\n", traffic_class);
                return -EINVAL;
        }