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.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: Google

Published: 2023-09-06T13:53:23.843Z

Updated: 2024-08-02T07:17:12.134Z

Reserved: 2023-08-07T13:02:26.235Z

Link: CVE-2023-4208

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2023-09-06T14:15:11.627

Modified: 2024-02-15T15:57:17.537

Link: CVE-2023-4208

cve-icon Redhat

Severity : Important

Publid Date: 2023-07-29T00:00:00Z

Links: CVE-2023-4208 - Bugzilla