CVE-2026-68156
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.68% probability · 51th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.