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.

Assisted-by: LLM
Fixes: f9dca80b98ca ("mac80211: fix AP_VLAN crypto tailroom calculation")
Reported-by: syzbot+de3ee5362db09487ea37@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=de3ee5362db09487ea37
Link: https://patch.msgid.link/20260908122838.201719-14-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

0 files changed, 0 insertions, 0 deletions