CVE-2023-4208

Description

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation. When u32_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. We recommend upgrading past commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81.

Weakness classification

• cve-coordination@google.com: CWE-416
• nvd@nist.gov: CWE-416

Primary references

• cve-coordination@google.com — Vendor Advisory
• cve-coordination@google.com — Vendor Advisory
• cve-coordination@google.com — Third Party Advisory
• cve-coordination@google.com — Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory