---
id: CVE-2026-68156
title: 'libceph: refresh auth->authorizer_buf{,_len} after authorizer update'
summary: |-
  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_au…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    2334e9997308305ee4fd508fdfe6086c4150ed60
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    79a273df64238a4ade8b709689a78589f755b8ef
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    26f814187abceee90dbb29a02133adb4786fbb13
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    9d37aec9ffe4e743dabc3f84502e9723e17a30d4
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    75e82e8944ac1efe9fdb88bd2f14d9a031282bdf
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    0060ec912292a550198d8d18ac95b433c92a7091
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    5ecfcd5c05866f185357700b81b461dae4f5ebb2
  - >-
    Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 <
    937d61f86d377a3aa578adae7a3dfcecdddf9d89
  - Linux 29c65a277a64645af853e8c9a9b3dda0ddc421e0
  - Linux d2c7223497cf8228416c70e3f4238ddd6c5bdf3c
  - Linux >= 3.4.50 < 3.5
  - Linux >= 3.9.7 < 3.10
  - Linux 3.10
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T15:45:09.780823Z'
published: '2026-08-10'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:53:01.050Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68156'
references:
  - url: 'https://git.kernel.org/stable/c/2334e9997308305ee4fd508fdfe6086c4150ed60'
  - url: 'https://git.kernel.org/stable/c/79a273df64238a4ade8b709689a78589f755b8ef'
  - url: 'https://git.kernel.org/stable/c/26f814187abceee90dbb29a02133adb4786fbb13'
  - url: 'https://git.kernel.org/stable/c/9d37aec9ffe4e743dabc3f84502e9723e17a30d4'
  - url: 'https://git.kernel.org/stable/c/75e82e8944ac1efe9fdb88bd2f14d9a031282bdf'
  - url: 'https://git.kernel.org/stable/c/0060ec912292a550198d8d18ac95b433c92a7091'
  - url: 'https://git.kernel.org/stable/c/5ecfcd5c05866f185357700b81b461dae4f5ebb2'
  - url: 'https://git.kernel.org/stable/c/937d61f86d377a3aa578adae7a3dfcecdddf9d89'
tags:
  - cve.org
epss: 0.00694
epssPercentile: 0.51973
ingestedAt: '2026-10-16T17:24:46.845Z'
---

## Overview

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.

## Affected

- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 2334e9997308305ee4fd508fdfe6086c4150ed60`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 79a273df64238a4ade8b709689a78589f755b8ef`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 26f814187abceee90dbb29a02133adb4786fbb13`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 9d37aec9ffe4e743dabc3f84502e9723e17a30d4`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 75e82e8944ac1efe9fdb88bd2f14d9a031282bdf`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 0060ec912292a550198d8d18ac95b433c92a7091`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 5ecfcd5c05866f185357700b81b461dae4f5ebb2`
- `Linux >= 0bed9b5c523d577378b6f83eab5835fe30c27208 < 937d61f86d377a3aa578adae7a3dfcecdddf9d89`
- `Linux 29c65a277a64645af853e8c9a9b3dda0ddc421e0`
- `Linux d2c7223497cf8228416c70e3f4238ddd6c5bdf3c`
- `Linux >= 3.4.50 < 3.5`
- `Linux >= 3.9.7 < 3.10`
- `Linux 3.10`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.