This is a note to let you know that I've just added the patch titled wifi: nl80211: reject iftype change with mesh ID change to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-nl80211-reject-iftype-change-with-mesh-id-change.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f78c1375339a291cba492a70eaf12ec501d28a8e Mon Sep 17 00:00:00 2001 From: Johannes Berg <johannes.berg@xxxxxxxxx> Date: Wed, 14 Feb 2024 20:08:35 +0100 Subject: wifi: nl80211: reject iftype change with mesh ID change From: Johannes Berg <johannes.berg@xxxxxxxxx> commit f78c1375339a291cba492a70eaf12ec501d28a8e 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@xxxxxxxxxxxxxxx Fixes: 29cbe68c516a ("cfg80211/mac80211: add mesh join/leave commands") Reported-by: syzbot+dd4779978217b1973180@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/wireless/nl80211.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3527,6 +3527,8 @@ static int nl80211_set_interface(struct if (ntype != NL80211_IFTYPE_MESH_POINT) return -EINVAL; + if (otype != NL80211_IFTYPE_MESH_POINT) + return -EINVAL; if (netif_running(dev)) return -EBUSY; Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are queue-5.4/wifi-nl80211-reject-iftype-change-with-mesh-id-change.patch