CVE-2023-4623

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.

Weakness classification

• CWE-416: Use After Free

Primary references

• cve-coordination@google.com — Third Party Advisory, VDB Entry
• cve-coordination@google.com — Issue Tracking, Mailing List, Patch, Vendor Advisory
• cve-coordination@google.com — Patch, Vendor Advisory
• cve-coordination@google.com — Mailing List, Third Party Advisory
• cve-coordination@google.com — Mailing List, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory, VDB Entry
• af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Mailing List, Patch, Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Patch, Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
• 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
• 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e