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🛡️ CVE-2023-52447 — kernel

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

bpf: Defer the free of inner map when necessary

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

bpf: Defer the free of inner map when necessary

When updating or deleting an inner map in map array or map htab, the map

may still be accessed by non-sleepable program or sleepable program.

However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map

directly through bpf_map_put(), if the ref-counter is the last one

(which is true for most cases), the inner map will be freed by

ops->map_free() in a kworker. But for now, most .map_free() callbacks

don't use synchronize_rcu() or its variants to wait for the elapse of a

RCU grace period, so after the invocation of ops->map_free completes,

the bpf program which is accessing the inner map may incur

use-after-free problem.

Fix the free of inner map by invoking bpf_map_free_deferred() after both

one RCU grace period and one tasks trace RCU grace period if the inner

map has been removed from the outer map before. The deferment is

accomplished by using call_rcu() or call_rcu_tasks_trace() when

releasing the last ref-counter of bpf map. The newly-added rcu_head

field in bpf_map shares the same storage space with work field to

reduce the size of bpf_map.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2023-52447 is recorded against 2 packages.

  • kernel (from 6.7.0 up to 6.7.2)
  • linux-kernel (from 6.7 up to 6.7.2)

Timeline and source

Published on 22 February 2024 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

cert-portal.siemens.com (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
lists.debian.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

CVE-2023-52447 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2024-02-22
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 6.7.0 6.7.2
linux-kernel 6.7 6.7.2

References

Similar Threats

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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