CVE-2023-6531: Kernel: gc's deletion of an skb races with unix_stream_read_generic() leading to uaf

Severity: high (CVSS 7.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-01-21 · updated 2026-08-06
Weakness: CWE-362

Description

A use-after-free flaw was found in the Linux Kernel due to a race problem in the unix garbage collector's deletion of SKB races with unix_stream_read_generic() on the socket that the SKB is queued on.

Affected products

Linux kernel: before 6.7; 6.7-rc1, 6.7-rc2, 6.7-rc3, 6.7-rc4 — fixed in 6.7
Red Hat Enterprise Linux: 9.0

How to fix

Upgrade to a fixed version: Linux kernel 6.7. Check the vendor advisory for mitigations.

References

https://access.redhat.com/errata/RHSA-2024:2394
https://access.redhat.com/security/cve/CVE-2023-6531
https://bugzilla.redhat.com/show_bug.cgi?id=2253034
https://lore.kernel.org/all/c716c88321939156909cfa1bd8b0faaf1c804103.1701868795.git.asml.silence@gmail.com/
http://packetstormsecurity.com/files/176533/Linux-Broken-Unix-GC-Interaction-Use-After-Free.html
https://access.redhat.com/errata/RHSA-2024:2394
https://access.redhat.com/security/cve/CVE-2023-6531
https://bugzilla.redhat.com/show_bug.cgi?id=2253034
https://lists.debian.org/debian-lts-announce/2024/01/msg00005.html
https://lore.kernel.org/all/c716c88321939156909cfa1bd8b0faaf1c804103.1701868795.git.asml.silence@gmail.com/

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