CVE-2023-1829: Use-after-free in tcindex (traffic control index filter) in the Linux Kernel

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-04-12 · updated 2026-07-29
Weakness: CWE-416

Description

A use-after-free vulnerability in the Linux Kernel traffic control index filter (tcindex) can be exploited to achieve local privilege escalation. The tcindex_delete function which does not properly deactivate filters in case of a perfect hashes while deleting the underlying structure which can later lead to double freeing the structure. A local attacker user can use this vulnerability to elevate its privileges to root. We recommend upgrading past commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/ .

Affected products

Linux kernel: before 4.14.308; from 4.15 before 4.19.276; from 4.20 before 5.4.235; from 5.5 before 5.10.173; from 5.11 before 5.15.100; from 5.16 before 6.1.18 — fixed in 4.14.308, 4.19.276, 5.10.173, 5.15.100, 5.4.235, 6.1.18

How to fix

Upgrade to a fixed version: Linux kernel 4.14.308, 4.19.276, 5.10.173, 5.15.100. Check the vendor advisory for mitigations.

References

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