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:sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls thechild qdisc's peek() operation before incrementing sch->q.qlen andsch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this maytrigger an immediate dequeue and potential packet drop. In such cases,qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backloghave not yet been updated, leading to inconsistent queue accounting. Thiscan leave an empty HFSC class in the active list, causing furtherconsequences like use-after-free.This patch fixes the bug by moving the increment of sch->q.qlen andsch->qstats.backlog before the call to the child qdisc's peek() operation.This ensures that queue length and backlog are always accurate when packetdrops or dequeues are triggered during the peek.
No PoCs from references.
- https://github.com/w4zu/Debian_security