CVE-2023-4623
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.
- Score
- CVSS 3.1 7.8 High
- Status
- Modified - cve-coordination@google.com
- Published
- 2023-09-06
- Last modified
- 2026-10-14
- Weaknesses
- CWE-416
Affected products
- Debian Linux (Debian)
- Kernel (Linux)
- Linux Kernel (Linux)
- Simatic S7-1500 Cpu 1518-4 Pndp Mfp (Siemens)
- Simatic S7-1500 Cpu 1518f-4 Pndp Mfp (Siemens)
- Simatic S7-1500 Tm Mfp - Gnulinux Subsystem (Siemens)
- Siplus S7-1500 Cpu 1518-4 Pndp Mfp (Siemens)
References
- 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
- https://cert-portal.siemens.com/productcert/html/ssa-794697.html
- https://cert-portal.siemens.com/productcert/html/ssa-398330.html
- https://cert-portal.siemens.com/productcert/html/ssa-769027.html
