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

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

[Linkai Gong]

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@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;
-- 
2.25.1

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

[Baochen Qiang]

On 8/11/2026 10:05 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@kylinos.cn>

Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>

Re: [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@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@oss.qualcomm.com>

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

[Jeff Johnson]

On Tue, 11 Aug 2026 10:05:23 +0800, 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.
> 
> [...]

Applied, thanks!

[1/1] wifi: ath12k: clear dangling channel pointers on error paths
      commit: 507478f6f93864978a399173d4f54c8a987c8235

Best regards,
-- 
Jeff Johnson <jeff.johnson@oss.qualcomm.com>