[PATCH] wifi: ath12k: fix reusing outside iterator in ath12k_wow_vif_set_wakeups()

[Jeff Johnson]

On 7/21/2024 8:33 PM, Baochen Qiang wrote:
> Smatch throws below warning:
> 
> 	drivers/net/wireless/ath/ath12k/wow.c:434 ath12k_wow_vif_set_wakeups()
> 	warn: reusing outside iterator: 'i'
> 
> 	drivers/net/wireless/ath/ath12k/wow.c
> 	    411         default:
> 	    412                 break;
> 	    413         }
> 	    414
> 	    415         for (i = 0; i < wowlan->n_patterns; i++) {
> 	                            ^^^^^^^^^^^^^^^^^^^^^^
> 	Here we loop until ->n_patterns
> 
> 	    416                 const struct cfg80211_pkt_pattern *eth_pattern = &patterns[i];
> 	    417                 struct ath12k_pkt_pattern new_pattern = {};
> 	    418
> 	    419                 if (WARN_ON(eth_pattern->pattern_len > WOW_MAX_PATTERN_SIZE))
> 	    420                         return -EINVAL;
> 	    421
> 	    422                 if (ar->ab->wow.wmi_conf_rx_decap_mode ==
> 	    423                     ATH12K_HW_TXRX_NATIVE_WIFI) {
> 	    424                         ath12k_wow_convert_8023_to_80211(ar, eth_pattern,
> 	    425                                                          &new_pattern);
> 	    426
> 	    427                         if (WARN_ON(new_pattern.pattern_len > WOW_MAX_PATTERN_SIZE))
> 	    428                                 return -EINVAL;
> 	    429                 } else {
> 	    430                         memcpy(new_pattern.pattern, eth_pattern->pattern,
> 	    431                                eth_pattern->pattern_len);
> 	    432
> 	    433                         /* convert bitmask to bytemask */
> 	--> 434                         for (i = 0; i < eth_pattern->pattern_len; i++)
> 	    435                                 if (eth_pattern->mask[i / 8] & BIT(i % 8))
> 	    436                                         new_pattern.bytemask[i] = 0xff;
> 
> 	This loop re-uses i and the loop ends with i == eth_pattern->pattern_len.
> 	This looks like a bug.
> 
> Change to use a new iterator 'j' for the inner loop to fix it.
> 
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4
> 
> Fixes: 4a3c212eee0e ("wifi: ath12k: add basic WoW functionalities")
> Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
> Closes: https://lore.kernel.org/all/d4975b95-9c43-45af-a0ab-80253f18c7f2@stanley.mountain/
> Signed-off-by: Baochen Qiang <quic_bqiang at quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson at quicinc.com>