CVSROOT: /cvs
Module name: src
Changes by: m...@cvs.openbsd.org 2017/12/21 05:09:38
Modified files:
sys/net80211 : ieee80211_pae_output.c
Log message:
Call if_start() directly to send the EAPOL key.
Using if_enqueue() here, from interrupt context, might result in
the packet beeing enqueued, incorrectly encrypted, on the TX ring.
This race has been recently exposed by the re-introduction of the
TX mitigation. It exists because the net80211 stack sets
IEEE80211_NODE_TXPROT on the node while processing the 3rd message,
assuming the answer has already been transmitted. However a CPU
returns from if_enqueue() it cannot assume that the send queue is
empty. So call if_start() to flush this queue.
Encrypting the 4th message of the 4way handshake with the new key
breaks WPA handshake as found the hardway by anton@.
Race analysed by dlg@, a lot of net80211 inputs and suggetions from
stsp@.
ok stsp@, dlg@
