From: Johannes Berg Date: Mon, 30 Dec 2024 08:14:07 +0000 (+0100) Subject: wifi: mac80211: prohibit deactivating all links X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7553477cbfd784b128297f9ed43751688415bbaa;p=users%2Fwilly%2Fxarray.git wifi: mac80211: prohibit deactivating all links In the internal API this calls this is a WARN_ON, but that should remain since internally we want to know about bugs that may cause this. Prevent deactivating all links in the debugfs write directly. Reported-by: syzbot+0c5d8e65f23569a8ffec@syzkaller.appspotmail.com Fixes: 3d9011029227 ("wifi: mac80211: implement link switching") Signed-off-by: Johannes Berg Link: https://patch.msgid.link/20241230091408.505bd125c35a.Ic3c1f9572b980a952a444cad62b09b9c6721732b@changeid Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c index a9bc2fd59f55..e7687a7b1683 100644 --- a/net/mac80211/debugfs_netdev.c +++ b/net/mac80211/debugfs_netdev.c @@ -727,7 +727,7 @@ static ssize_t ieee80211_if_parse_active_links(struct ieee80211_sub_if_data *sda { u16 active_links; - if (kstrtou16(buf, 0, &active_links)) + if (kstrtou16(buf, 0, &active_links) || !active_links) return -EINVAL; return ieee80211_set_active_links(&sdata->vif, active_links) ?: buflen;