From ce543e782210b38cdab18a261d526ccacf32e7cc Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 30 Dec 2024 09:14:07 +0100
Subject: [PATCH] wifi: mac80211: prohibit deactivating all links
[ Upstream commit 7553477cbfd784b128297f9ed43751688415bbaa ]
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 <johannes.berg@intel.com>
Link: https://patch.msgid.link/20241230091408.505bd125c35a.Ic3c1f9572b980a952a444cad62b09b9c6721732b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/debugfs_netdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index 8ced615add712..f8416965c2198 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -588,7 +588,7 @@ 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;
--
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