[PATCH v2] wifi: ath12k: clear dangling channel pointers on error paths

[Rameshkumar Sundaram]

On 8/11/2026 7:35 AM, Linkai Gong wrote:
> On failure, ath12k_mac_setup_channels_rates() frees band channel
> arrays but leaves the pointers set, or clears the wrong band after a
> copy-paste typo (6 GHz free paired with a 2 GHz NULL). Clear the
> matching sbands[].channels pointer after each kfree().
> 
> Compile tested only.
> 
> Signed-off-by: Linkai Gong <gonglinkai at kylinos.cn>
> ---
> v2:
> - reword commit message (dangling pointers + typo, not double-free)
> - drop Fixes tag
> - note compile tested only
> 
> v1: https://lore.kernel.org/all/20260731093816.1771338-1-gonglinkai@kylinos.cn/
> 
>   drivers/net/wireless/ath/ath12k/mac.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index a0928890671a..5468a8d2d5d5 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -14275,6 +14275,7 @@ static int ath12k_mac_setup_channels_rates(struct ath12k *ar,
>   					   sizeof(ath12k_6ghz_channels), GFP_KERNEL);
>   			if (!channels) {
>   				kfree(ar->mac.sbands[NL80211_BAND_2GHZ].channels);
> +				ar->mac.sbands[NL80211_BAND_2GHZ].channels = NULL;
>   				return -ENOMEM;
>   			}
>   
> @@ -14325,7 +14326,9 @@ static int ath12k_mac_setup_channels_rates(struct ath12k *ar,
>   					   GFP_KERNEL);
>   			if (!channels) {
>   				kfree(ar->mac.sbands[NL80211_BAND_2GHZ].channels);
> +				ar->mac.sbands[NL80211_BAND_2GHZ].channels = NULL;
>   				kfree(ar->mac.sbands[NL80211_BAND_6GHZ].channels);
> +				ar->mac.sbands[NL80211_BAND_6GHZ].channels = NULL;
>   				return -ENOMEM;
>   			}
>   
> @@ -14365,7 +14368,7 @@ static int ath12k_mac_setup_channels_rates(struct ath12k *ar,
>   					kfree(ar->mac.sbands[NL80211_BAND_2GHZ].channels);
>   					ar->mac.sbands[NL80211_BAND_2GHZ].channels = NULL;
>   					kfree(ar->mac.sbands[NL80211_BAND_6GHZ].channels);
> -					ar->mac.sbands[NL80211_BAND_2GHZ].channels = NULL;
> +					ar->mac.sbands[NL80211_BAND_6GHZ].channels = NULL;
>   					kfree(channels);
>   					band->channels = NULL;
>   					return ret;


Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram at oss.qualcomm.com>