The processing of the struct cfg80211_sar_specs::sub_specs flexible
array requires its counter, num_sub_specs, to be assigned before the
loop in nl80211_set_sar_specs(). Leave the final assignment after the
loop in place in case fewer ended up in the array.

Fixes: aa4ec06c455d ("wifi: cfg80211: use __counted_by where appropriate")
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Dmitry Antipov <dmantipov@yandex.ru>
Cc: <linux-wireless@vger.kernel.org>
---
 net/wireless/nl80211.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 1c808b08b747..db8b089454ca 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -17559,6 +17559,7 @@ static int nl80211_set_sar_specs(struct sk_buff *skb, struct genl_info *info)
 	if (!sar_spec)
 		return -ENOMEM;
 
+	sar_spec->num_sub_specs = specs;
 	sar_spec->type = type;
 	specs = 0;
 	nla_for_each_nested(spec_list, tb[NL80211_SAR_ATTR_SPECS], rem) {
-- 
2.34.1

On 21/07/25 12:31, Kees Cook wrote:
> The processing of the struct cfg80211_sar_specs::sub_specs flexible
> array requires its counter, num_sub_specs, to be assigned before the
> loop in nl80211_set_sar_specs(). Leave the final assignment after the
> loop in place in case fewer ended up in the array.
> 
> Fixes: aa4ec06c455d ("wifi: cfg80211: use __counted_by where appropriate")
> Signed-off-by: Kees Cook <kees@kernel.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
-Gustavo

> ---
> Cc: Johannes Berg <johannes@sipsolutions.net>
> Cc: Dmitry Antipov <dmantipov@yandex.ru>
> Cc: <linux-wireless@vger.kernel.org>
> ---
>   net/wireless/nl80211.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
> index 1c808b08b747..db8b089454ca 100644
> --- a/net/wireless/nl80211.c
> +++ b/net/wireless/nl80211.c
> @@ -17559,6 +17559,7 @@ static int nl80211_set_sar_specs(struct sk_buff *skb, struct genl_info *info)
>   	if (!sar_spec)
>   		return -ENOMEM;
>   
> +	sar_spec->num_sub_specs = specs;
>   	sar_spec->type = type;
>   	specs = 0;
>   	nla_for_each_nested(spec_list, tb[NL80211_SAR_ATTR_SPECS], rem) {