Linux Kernel Vulnerability in libceph Affects System Integrity

CVE-2025-39880

What is CVE-2025-39880?

A vulnerability in the Linux kernel's libceph component involves improper handling of union member accesses in the messenger.c code. The issue arises when generic code attempts to read from and write to the con->v1 union member without verifying its active status, especially on 64-bit systems. This oversight can lead to potentially invalid values being read, particularly with the con->v1.auth_retry and con->v2.out_iter overlapping, which may lead to benign yet disruptive effects like the invalidation of authorizer tickets. More critically, writes to overlapping memory locations, such as con->v1.connect_seq with con->v2.conn_bufs, could cause serious operational issues, although these scenarios are infrequent.

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