CVE-2025-39880
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-23

Last updated on: 2025-11-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: libceph: fix invalid accesses to ceph_connection_v1_info There is a place where generic code in messenger.c is reading and another place where it is writing to con->v1 union member without checking that the union member is active (i.e. msgr1 is in use). On 64-bit systems, con->v1.auth_retry overlaps with con->v2.out_iter, so such a read is almost guaranteed to return a bogus value instead of 0 when msgr2 is in use. This ends up being fairly benign because the side effect is just the invalidation of the authorizer and successive fetching of new tickets. con->v1.connect_seq overlaps with con->v2.conn_bufs and the fact that it's being written to can cause more serious consequences, but luckily it's not something that happens often.
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Meta Information
Published
2025-09-23
Last Modified
2025-11-03
Generated
2026-06-16
AI Q&A
2025-09-23
EPSS Evaluated
2026-06-15
NVD
CVE-2025-39880
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel 6.1.153
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Exploitability
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability in the Linux kernel's libceph component involves invalid accesses to the ceph_connection_v1_info structure. Specifically, generic code reads and writes to a union member without verifying if that member is active. On 64-bit systems, overlapping fields in the union can cause reads to return incorrect values and writes to potentially cause more serious issues, although these are rare. The main side effect is invalidation of the authorizer and repeated fetching of new tickets.

Impact Analysis

The impact is generally limited. The invalid read causes the authorizer to be invalidated, leading to successive fetching of new tickets, which may affect performance or cause minor disruptions. The write overlap could cause more serious consequences, but this is infrequent. Overall, the vulnerability is fairly benign.

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