kernel: Linux kernel: Denial of Service in QFQ scheduler via child qlen manipulation

A flaw was found in the Linux kernel's Quick Fair Queuing QFQ scheduler. The QFQ class deactivation logic incorrectly relies on a child qdisc's queue length qlen to determine if a class is active. A local user with CAPNETADMIN capabilities can manipulate the child qlen into an unexpected state...

kernel: Linux kernel: Denial of Service in QFQ scheduler via child qlen manipulation

A flaw was found in the Linux kernel's Quick Fair Queuing QFQ scheduler. The QFQ class deactivation logic incorrectly relies on a child qdisc's queue length qlen to determine if a class is active. A local user with CAPNETADMIN capabilities can manipulate the child qlen into an unexpected state...

Astra Linux – Vulnerabilities in Linux, Linux-5.10, Linux-5.15

The qfqchangeclass function in net/sched/schqfq.c in the Linux kernel before version 6.2.13 allows a out-of-bounds write vulnerability, as lmax can exceed QFQMINLMAX...

Astra Linux – Vulnerabilities in Linux, Linux-5.10, Linux-5.15, Linux-6.1

A use-after-free vulnerability exists in the Linux kernel’s net/sched: schqfq component, which can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers a use-after-free in qfqdequeue, due to the incorrect .pe...

Astra Linux – Vulnerabilities in Linux 5.10, Linux 5.15, Linux 6.1

In the Linux kernel, the following vulnerability has been resolved: net/sched: schqfq: do not free existing class in qfqchangeclass This fix addresses the issue with the qfqchangeclass function. The cl-qdisc and cl fields should only be freed if a new class and qdisc are allocated; otherwise,...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1, and Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: net/sched: schqfq: Fixed a null dereference in aggdequeue. To prevent a potential crash in aggdequeue when cl-qdisc-ops-peekcl-qdisc returns NULL, we check the returned value before using it, similar to the existing approach in...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1, and Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: net/sched: qfq: Use clisactive to determine whether a class is active in qfqrmfromag. This is more of a preventive patch aimed at making the code more consistent and preventing possible exploits that involve manipulating child ql...

Linux Kernel QFQ Plus Scheduler Use-After-Free Local Privilege Escalation Vulnerability

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of qfqclas...

Unity Linux 20.1050a Security Update: kernel (UTSA-2026-053273)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-053273 advisory. In the Linux kernel, the following vulnerability has been resolved: net/sched: Enforce that teql can only be used as root qdisc Design intent of teql is that it is...

SUSE CVE-2026-80630

In the Linux kernel, the following vulnerability has been resolved: net/sched: schfqcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever fqcodel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog befo...

UBUNTU-CVE-2026-80630

In the Linux kernel, the following vulnerability has been resolved: net/sched: schfqcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever fqcodel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog befo...

CVE-2026-80630

In the Linux kernel, the following vulnerability has been resolved: net/sched: schfqcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever fqcodel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog befo...

CVE-2026-80630 net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen

In the Linux kernel, the following vulnerability has been resolved: net/sched: schfqcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever fqcodel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog befo...

EUVD-2026-67506

In the Linux kernel, the following vulnerability has been resolved: net/sched: schfqcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever fqcodel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog befo...

CVE-2026-80630

CVE-2026-80630 is a vulnerability in the Linux kernel's fq_codel traffic control qdisc (net/sched/sch_fq_codel). During the peek operation, the code calls qdisc_tree_reduce_backlog before reincrementing qlen. If qlen momentarily drops to zero while peek still returns a packet, the parent qdisc's ...

CVE-2026-80630 net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restoring qlen

In the Linux kernel, the following vulnerability has been resolved: net/sched: schfqcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever fqcodel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog befo...

PT-2026-82930

Name of the Vulnerable Software and Affected Versions Linux kernel affected versions not specified Description An issue exists in the sch fq codel scheduler where qdisc tree reduce backlog is called during a peek operation before the qlen variable is restored. If qlen drops to zero while the peek...

SUSE CVE-2026-72036

In the Linux kernel, the following vulnerability has been resolved: net/sched: schmultiq: Replace direct dequeue call with peek and qdiscdequeuepeeked multiqdequeue takes a packet from a band's child with a direct -dequeue call after multiqpeek peeked it. When the child is non-work-conserving the...

SUSE CVE-2026-72035

In the Linux kernel, the following vulnerability has been resolved: net/sched: schtaprio: Replace direct dequeue call with peek and qdiscdequeuepeeked When taprio's software path peeks a non-work-conserving child qdisc, the child stashes the peeked skb in its gsoskb; tapriodequeuefromtxq then tak...

SUSE CVE-2026-74267

In the Linux kernel, the following vulnerability has been resolved: net/sched: schcodel: Do not call qdisctreereducebacklog during peek before restoring qlen Whenever codel drops packets during peek, it calls qdisctreereducebacklog. An issue arises because it calls qdisctreereducebacklog before i...