diff --git a/net/wireless/pmsr.c b/net/wireless/pmsr.c index d1e2fae5bc0e..97449bcb9a22 100644 --- a/net/wireless/pmsr.c +++ b/net/wireless/pmsr.c @@ -420,6 +420,7 @@ int nl80211_pmsr_start(struct sk_buff *skb, struct genl_info *info) const struct cfg80211_pmsr_capabilities *capa; struct cfg80211_pmsr_request *req; struct nlattr *peers, *peer; + u64 cookie; capa = rdev->wiphy.pmsr_capa; @@ -521,14 +522,27 @@ int nl80211_pmsr_start(struct sk_buff *skb, struct genl_info *info) } req->cookie = cfg80211_assign_cookie(rdev); req->nl_portid = info->snd_portid; + cookie = req->cookie; + + /* + * Add to the list before the driver call; under races or broken + * drivers, completion may free the request before rdev_start_pmsr() + * returns. Use the saved cookie below. + */ + spin_lock_bh(&wdev->pmsr_lock); + list_add_tail(&req->list, &wdev->pmsr_list); + spin_unlock_bh(&wdev->pmsr_lock); err = rdev_start_pmsr(rdev, wdev, req); - if (err) + if (err) { + /* An error return leaves the request owned by this path. */ + spin_lock_bh(&wdev->pmsr_lock); + list_del(&req->list); + spin_unlock_bh(&wdev->pmsr_lock); goto out_err; + } - list_add_tail(&req->list, &wdev->pmsr_list); - - nl_set_extack_cookie_u64(info->extack, req->cookie); + nl_set_extack_cookie_u64(info->extack, cookie); return 0; out_err: kfree(req);