In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: reset the AP_VLAN tailroom counter on ifdown
On ifup, AP_VLAN interfaces get crypto_tx_tailroom_needed_cnt from
the AP interface, but it’s never decremented again unless the AP is
also brought down. Thus, bringing the same AP_VLAN up again will
increment the counter again and eventually hit the sanity check:
WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
master->crypto_tx_tailroom_needed_cnt);
Reset it on ifdown to avoid that.
