Re: [PATCH] wifi: nl80211: Set num_sub_specs before looping through sub_specs

From: Gustavo A. R. Silva
Date: Mon Jul 21 2025 - 15:00:17 EST




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@xxxxxxxxxx>

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

Thanks!
-Gustavo

---
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: Dmitry Antipov <dmantipov@xxxxxxxxx>
Cc: <linux-wireless@xxxxxxxxxxxxxxx>
---
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) {