CVE-2023-52447

Advisory lineage Upstream: 0 Downstream: 31
Modified
Published: 22 Feb 2024, 16:21
Last modified:12 May 2026, 11:21

Vulnerability Summary

Overall Risk (default)
medium
27/100
CVSS Score
6.7 MEDIUM
v3.1 (cve.org)
EPSS Score
0.01% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

22 Feb 2024, 16:21
Published
Vulnerability first disclosed
12 May 2026, 11:21
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 6.7CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 2%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • linux•linux

    ≥ bba1dc0b55ac462d24ed1228ad49800c238cd6d7, < 90c445799fd1dc214d7c6279c144e33a35e29ef2 | ≥ bba1dc0b55ac462d24ed1228ad49800c238cd6d7, < 37d98fb9c3144c0fddf7f6e99aece9927ac8dce6 | ≥ bba1dc0b55ac462d24ed1228ad49800c238cd6d7, < 62fca83303d608ad4fec3f7428c8685680bb01b0 | ≥ bba1dc0b55ac462d24ed1228ad49800c238cd6d7, < f91cd728b10c51f6d4a39957ccd56d1e802fc8ee | ≥ bba1dc0b55ac462d24ed1228ad49800c238cd6d7, < bfd9b20c4862f41d4590fde11d70a5eeae53dcc5 | ≥ bba1dc0b55ac462d24ed1228ad49800c238cd6d7, < 876673364161da50eed6b472d746ef88242b2368 | 5.9

  • linux•linux_kernel

    ≥ 5.9.0, < 5.10.214 | ≥ 5.11, < 5.15.153 | ≥ 5.16, < 6.1.75 | ≥ 6.2, < 6.6.14 | ≥ 6.7, < 6.7.2

References (8)