vulnerability
Amazon Linux AMI: CVE-2023-4623: Security patch for kernel (ALAS-2023-1838)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 7 | (AV:L/AC:L/Au:S/C:C/I:C/A:C) | Sep 6, 2023 | Oct 7, 2023 | May 21, 2025 |
Severity
7
CVSS
(AV:L/AC:L/Au:S/C:C/I:C/A:C)
Published
Sep 6, 2023
Added
Oct 7, 2023
Modified
May 21, 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.
Solution
amazon-linux-upgrade-kernel
References
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