medium 5.5

CVE-2023-52986 json

bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener

published 2025-03-27 19 mo ago modified 2026-11-05 3 d ago also EUVD-2023-59734

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 20%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

A listening socket linked to a sockmap has its sk_prot overridden. It points to one of the struct proto variants in tcp_bpf_prots. The variant depends on the socket's family and which sockmap programs are attached.

A child socket cloned from a TCP listener initially inherits their sk_prot. But before cloning is finished, we restore the child's proto to the listener's original non-tcp_bpf_prots one. This happens in tcp_create_openreq_child -> tcp_bpf_clone.

Today, in tcp_bpf_clone we detect if the child's proto should be restored by checking only for the TCP_BPF_BASE proto variant. This is not correct. The sk_prot of listening socket linked to a sockmap can point to to any variant in tcp_bpf_prots.

If the listeners sk_prot happens to be not the TCP_BPF_BASE variant, then the child socket unintentionally is left if the inherited sk_prot by tcp_bpf_clone.

This leads to issues like infinite recursion on close [1], because the child state is otherwise not set up for use with tcp_bpf_prot operations.

Adjust the check in tcp_bpf_clone to detect all of tcp_bpf_prots variants.

Note that it wouldn't be sufficient to check the socket state when overriding the sk_prot in tcp_bpf_update_proto in order to always use the TCP_BPF_BASE variant for listening sockets. Since commit b8b8315e39ff ("bpf, sockmap: Remove unhash handler for BPF sockmap usage") it is possible for a socket to transition to TCP_LISTEN state while already linked to a sockmap, e.g. connect() -> insert into map -> connect(AF_UNSPEC) -> listen().

[1]: https://lore.kernel.org/all/00000000000073b14905ef2e7401@google.com/

Patch / fix

fixed in 1 distros 4 links 4

Linux Linux 5.10.168, 5.15.93, 6.1.11, 6.2

debian ubuntu red hat suse

linux Debian 14, Debian 13, Debian 12 6.1.11-1

debian advisories DEBIAN-CVE-2023-52986

linux Ubuntu 22.04 LTS 5.15.0-72.79
linux-aws Ubuntu 22.04 LTS 5.15.0-1036.40
linux-gcp Ubuntu 22.04 LTS 5.15.0-1034.42
linux-gke Ubuntu 22.04 LTS 5.15.0-1033.38
linux-ibm Ubuntu 22.04 LTS 5.15.0-1030.33
linux-kvm Ubuntu 22.04 LTS 5.15.0-1033.38
linux-azure Ubuntu 22.04 LTS 5.15.0-1038.45
linux-gkeop Ubuntu 22.04 LTS 5.15.0-1020.25

ubuntu advisories UBUNTU-CVE-2023-52986

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel RHEL 9 5.14.0-362.8.1.el9_3
rv RHEL 9 5.14.0-362.8.1.el9_3
perf RHEL 9 5.14.0-362.8.1.el9_3
rtla RHEL 9 5.14.0-362.8.1.el9_3
bpftool RHEL 9 7.2.0-362.8.1.el9_3
libperf RHEL 9 5.14.0-362.8.1.el9_3
kernel-rt RHEL 9 5.14.0-362.8.1.el9_3
kernel-64k RHEL 9 5.14.0-362.8.1.el9_3

red hat advisories RHSA-2023:6583

kernel-rt SLE Micro 5.5 5.14.21-150500.13.94.1
kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.94.1
kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.103.1
kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.103.1
kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.103.1
kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.103.1
kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.103.1
kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.103.1.150500.6.49.1

suse advisories SUSE-SU-2025:01640-1 SUSE-SU-2025:01620-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-52986 updated 2026-11-06 cvss 4.1

kernel: bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener

Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
affected: no fix available “Fix deferred”
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernel
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 3 d ago (2026-11-05)

Exploit prediction

0.28% chance of exploitation in the next 30 days, higher than 20% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Linux Linux

Classification

Weakness

CWE-674 Uncontrolled Recursion

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2023-52986
NVD CVE-2023-52986

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary