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CVE-2023-52447

MEDIUM
Published 2024-02-22T16:21:39.032Z
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CVSS Score

V3.1
6.7
/10
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Base Score Metrics
Exploitability: N/A Impact: N/A

EPSS Score

v2025.03.14
0.000
probability
of exploitation in the wild

There is a 0.0% chance that this vulnerability will be exploited in the wild within the next 30 days.

Updated: 2025-06-25
Exploit Probability
Percentile: 0.013
Higher than 1.3% of all CVEs

Attack Vector Metrics

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED

Impact Metrics

Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH

Description

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.

Available Exploits

No exploits available for this CVE.

Related News

No news articles found for this CVE.

Affected Products

GitHub Security Advisories

Community-driven vulnerability intelligence from GitHub

⚠ Unreviewed HIGH

GHSA-wvjr-h8mr-f8gw

Advisory Details

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.

CVSS Scoring

CVSS Score

7.5

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Advisory provided by GitHub Security Advisory Database. Published: February 22, 2024, Modified: June 26, 2024

References

Published: 2024-02-22T16:21:39.032Z
Last Modified: 2025-05-04T07:36:44.024Z
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