From 45fcef8b727b6f171bc5443e8153181a367d7a15 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 29 Mar 2019 08:56:22 +0100 Subject: [PATCH] mac80211_hwsim: calculate if_combination.max_interfaces If we just set this to 2048, and have multiple limits you can select from, the total number might run over and cause a warning in cfg80211. This doesn't make sense, so we just calculate the total max_interfaces now. Reported-by: syzbot+8f91bd563bbff230d0ee@syzkaller.appspotmail.com Fixes: 99e3a44bac37 ("mac80211_hwsim: allow setting iftype support") Signed-off-by: Johannes Berg --- drivers/net/wireless/mac80211_hwsim.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 0838af04d681..524eb5805995 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -2644,7 +2644,7 @@ static int mac80211_hwsim_new_radio(struct genl_info *info, enum nl80211_band band; const struct ieee80211_ops *ops = &mac80211_hwsim_ops; struct net *net; - int idx; + int idx, i; int n_limits = 0; if (WARN_ON(param->channels > 1 && !param->use_chanctx)) @@ -2768,12 +2768,23 @@ static int mac80211_hwsim_new_radio(struct genl_info *info, goto failed_hw; } + data->if_combination.max_interfaces = 0; + for (i = 0; i < n_limits; i++) + data->if_combination.max_interfaces += + data->if_limits[i].max; + data->if_combination.n_limits = n_limits; - data->if_combination.max_interfaces = 2048; data->if_combination.limits = data->if_limits; - hw->wiphy->iface_combinations = &data->if_combination; - hw->wiphy->n_iface_combinations = 1; + /* + * If we actually were asked to support combinations, + * advertise them - if there's only a single thing like + * only IBSS then don't advertise it as combinations. + */ + if (data->if_combination.max_interfaces > 1) { + hw->wiphy->iface_combinations = &data->if_combination; + hw->wiphy->n_iface_combinations = 1; + } if (param->ciphers) { memcpy(data->ciphers, param->ciphers, -- 2.30.2