CVE-2026-68156

Description

In the Linux kernel, the following vulnerability has been resolved: libceph: refresh auth->authorizer_buf{,_len} after authorizer update ceph_x_create_authorizer() caches au->buf->vec.iov_base and au->buf->vec.iov_len in struct ceph_auth_handshake. These cached values are then used by the messenger connect code when sending the authorizer. ceph_x_update_authorizer() can rebuild the authorizer when a newer service ticket is available. If the rebuilt authorizer no longer fits in the existing buffer, ceph_x_build_authorizer() drops its reference to au->buf and allocates a new one. If this is the final reference, ceph_buffer_put() frees the old ceph_buffer and its vec.iov_base, but auth->authorizer_buf still points at that freed memory. A subsequent msgr1 reconnect can therefore queue the stale pointer and trigger a KASAN slab-use-after-free in _copy_from_iter() while tcp_sendmsg() copies the authorizer. Refresh auth->authorizer_buf and auth->authorizer_buf_len after a successful authorizer rebuild so the messenger sends the current buffer.

CVSS 3.1 breakdown

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

• https://git.kernel.org/stable/c/0060ec912292a550198d8d18ac95b433c92a7091
• https://git.kernel.org/stable/c/2334e9997308305ee4fd508fdfe6086c4150ed60
• https://git.kernel.org/stable/c/26f814187abceee90dbb29a02133adb4786fbb13
• https://git.kernel.org/stable/c/5ecfcd5c05866f185357700b81b461dae4f5ebb2
• https://git.kernel.org/stable/c/75e82e8944ac1efe9fdb88bd2f14d9a031282bdf
• https://git.kernel.org/stable/c/79a273df64238a4ade8b709689a78589f755b8ef
• https://git.kernel.org/stable/c/937d61f86d377a3aa578adae7a3dfcecdddf9d89
• https://git.kernel.org/stable/c/9d37aec9ffe4e743dabc3f84502e9723e17a30d4

Frequently asked