wifi: nl80211: reject iftype change with mesh ID change

commit f78c137533 upstream.

It's currently possible to change the mesh ID when the
interface isn't yet in mesh mode, at the same time as
changing it into mesh mode. This leads to an overwrite
of data in the wdev->u union for the interface type it
currently has, causing cfg80211_change_iface() to do
wrong things when switching.

We could probably allow setting an interface to mesh
while setting the mesh ID at the same time by doing a
different order of operations here, but realistically
there's no userspace that's going to do this, so just
disallow changes in iftype when setting mesh ID.

Cc: stable@vger.kernel.org
Fixes: 29cbe68c51 ("cfg80211/mac80211: add mesh join/leave commands")
Reported-by: syzbot+dd4779978217b1973180@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johannes Berg 2024-02-14 20:08:35 +01:00 committed by Greg Kroah-Hartman
parent abd32d7f5c
commit 930e826962
1 changed files with 2 additions and 0 deletions

View File

@ -4137,6 +4137,8 @@ static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
if (ntype != NL80211_IFTYPE_MESH_POINT)
return -EINVAL;
if (otype != NL80211_IFTYPE_MESH_POINT)
return -EINVAL;
if (netif_running(dev))
return -EBUSY;