CVE-2025-39880
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
In the Linux kernel, an invalid access bug was found in the libceph library to the ceph_connection_v1_info union. Generic code in messenger.c reads and writes to the v1 union member without checking if it is active (i.e., msgr1 is in use). This can lead to reading invalid values or writing to overlapping fields.
Risk Assessment
Invalid memory access can lead to unexpected behavior, such as authorizer invalidation and fetching new tickets, potentially affecting Ceph connection stability and security.
Recommendation
Apply the kernel patch that fixes CVE-2025-39880. Update your system to the latest stable kernel version.
Original NVD description (English source)
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.