vulnerability

Oracle Linux: CVE-2023-4623: ELBA-2024-12467: Unbreakable Enterprise kernel bug fix update (NA) (Multiple Advisories)

Severity
7
CVSS
(AV:L/AC:L/Au:S/C:C/I:C/A:C)
Published
Sep 6, 2023
Added
Dec 12, 2023
Modified
Jul 16, 2025

Description

A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.
If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.
We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.
A use-after-free flaw was found in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component that can be exploited to achieve local privilege escalation. If a class with a link-sharing curve, for example, with the HFSC_FSC flag set, has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free issue.

Solutions

oracle-linux-upgrade-kerneloracle-linux-upgrade-kernel-uek
Title
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