Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limitThe following setup can trigger a WARNING in htb_activate due tothe condition: !cl->leaf.q->q.qlentc qdisc del dev lo roottc qdisc add dev lo root handle 1: htb default 1tc class add dev lo parent 1: classid 1:1 \ htb rate 64bittc qdisc add dev lo parent 1:1 handle f: \ cake memlimit 1bping -I lo -f -c1 -s64 -W0.001 127.0.0.1This is because the low memlimit leads to a low buffer_limit, whichcauses packet dropping. However, cake_enqueue still returnsNET_XMIT_SUCCESS, causing htb_enqueue to call htb_activate with anempty child qdisc. We should return NET_XMIT_CN when packets aredropped from the same tin and flow.I do not believe return value of NET_XMIT_CN is necessary for packetdrops in the case of ack filtering, as that is meant to optimizeperformance, not to signal congestion.
No PoCs from references.
- https://github.com/w4zu/Debian_security