CVE-2023-4208

NameCVE-2023-4208
DescriptionA 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-3710-1, DSA-5492-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)buster4.19.249-2vulnerable
buster (security)4.19.304-1fixed
bullseye5.10.209-2fixed
bullseye (security)5.10.205-2fixed
bookworm6.1.76-1fixed
bookworm (security)6.1.69-1fixed
trixie6.6.15-2fixed
sid6.7.7-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebuster4.19.304-1DLA-3710-1
linuxsourcebullseye5.10.191-1
linuxsourcebookworm6.1.52-1DSA-5492-1
linuxsource(unstable)6.4.11-1

Notes

https://git.kernel.org/linus/3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81 (6.5-rc5)

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