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Fencer Vulns
high 7.8

CVE-2023-52483 json

mctp: perform route lookups under a RCU read-side lock

published 2024-02-29 2 y ago modified 2026-08-05 3 mo ago also EUVD-2023-57108

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

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

mctp: perform route lookups under a RCU read-side lock

Our current route lookups (mctp_route_lookup and mctp_route_lookup_null) traverse the net's route list without the RCU read lock held. This means the route lookup is subject to preemption, resulting in an potential grace period expiry, and so an eventual kfree() while we still have the route pointer.

Add the proper read-side critical section locks around the route lookups, preventing premption and a possible parallel kfree.

The remaining net->mctp.routes accesses are already under a rcu_read_lock, or protected by the RTNL for updates.

Based on an analysis from Sili Luo <rootlab@huawei.com>, where introducing a delay in the route lookup could cause a UAF on simultaneous sendmsg() and route deletion.

Patch / fix

  • Linux Linux 5.15.137, 6.1.59, 6.5.8, 6.6
  • linux Debian 12 6.1.64-1
  • linux Debian 14, Debian 13 6.5.8-1

debian advisories DEBIAN-CVE-2023-52483

  • linux Ubuntu 22.04 LTS 5.15.0-100.110
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1056.61
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1053.61
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1052.57
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1048.51
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1052.57
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1058.66
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1038.44

ubuntu advisories UBUNTU-CVE-2023-52483

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-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-9.1
  • kernel-source Linux Micro 6.0 6.4.0-18.1
  • kernel-default Linux Micro 6.0 6.4.0-18.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-18.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.5.4
  • kernel-syms-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.5.1

suse advisories SUSE-SU-2025:20028-1SUSE-SU-2025:20008-1SUSE-SU-2024:2135-1

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-2023-52483 updated cvss 7.8

kernel: mctp: perform route lookups under a RCU read-side lock

  • 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
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more
    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
2 y ago

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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.