Use After Free Affecting kernel package, versions <0:4.14.326-245.539.amzn2
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Test your applications- Snyk ID SNYK-AMZN2-KERNEL-5936166
- published 6 Oct 2023
- disclosed 6 Sep 2023
Introduced: 6 Sep 2023
CVE-2023-4623 Open this link in a new tabHow to fix?
Upgrade Amazon-Linux:2 kernel to version 0:4.14.326-245.539.amzn2 or higher.
This issue was patched in ALAS2-2023-2264.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel package and not the kernel package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2 relevant fixed versions and status.
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.
References
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4623
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b3d26c5702c7d6c45456326e56d2ccf3f103e60f
- https://kernel.dance/b3d26c5702c7d6c45456326e56d2ccf3f103e60f
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
- http://packetstormsecurity.com/files/175963/Kernel-Live-Patch-Security-Notice-LSN-0099-1.html
- https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html