From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-68156: libceph: refresh auth->authorizer_buf{,_len} after authorizer update
Date: Mon, 10 Aug 2026 13:57:53 +0200 [thread overview]
Message-ID: <2026081003-CVE-2026-68156-72bf@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
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.
The Linux kernel CVE team has assigned CVE-2026-68156 to this issue.
Affected and fixed versions
===========================
Issue introduced in 3.10 with commit 0bed9b5c523d577378b6f83eab5835fe30c27208 and fixed in 6.6.148 with commit 9d37aec9ffe4e743dabc3f84502e9723e17a30d4
Issue introduced in 3.10 with commit 0bed9b5c523d577378b6f83eab5835fe30c27208 and fixed in 6.12.101 with commit 75e82e8944ac1efe9fdb88bd2f14d9a031282bdf
Issue introduced in 3.10 with commit 0bed9b5c523d577378b6f83eab5835fe30c27208 and fixed in 6.18.42 with commit 0060ec912292a550198d8d18ac95b433c92a7091
Issue introduced in 3.10 with commit 0bed9b5c523d577378b6f83eab5835fe30c27208 and fixed in 7.1.6 with commit 5ecfcd5c05866f185357700b81b461dae4f5ebb2
Issue introduced in 3.10 with commit 0bed9b5c523d577378b6f83eab5835fe30c27208 and fixed in 7.2-rc5 with commit 937d61f86d377a3aa578adae7a3dfcecdddf9d89
Issue introduced in 3.4.50 with commit 29c65a277a64645af853e8c9a9b3dda0ddc421e0
Issue introduced in 3.9.7 with commit d2c7223497cf8228416c70e3f4238ddd6c5bdf3c
Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.
Unaffected versions might change over time as fixes are backported to
older supported kernel versions. The official CVE entry at
https://cve.org/CVERecord/?id=CVE-2026-68156
will be updated if fixes are backported, please check that for the most
up to date information about this issue.
Affected files
==============
The file(s) affected by this issue are:
net/ceph/auth_x.c
Mitigation
==========
The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes. Individual
changes are never tested alone, but rather are part of a larger kernel
release. Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all. If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
https://git.kernel.org/stable/c/9d37aec9ffe4e743dabc3f84502e9723e17a30d4
https://git.kernel.org/stable/c/75e82e8944ac1efe9fdb88bd2f14d9a031282bdf
https://git.kernel.org/stable/c/0060ec912292a550198d8d18ac95b433c92a7091
https://git.kernel.org/stable/c/5ecfcd5c05866f185357700b81b461dae4f5ebb2
https://git.kernel.org/stable/c/937d61f86d377a3aa578adae7a3dfcecdddf9d89
reply other threads:[~2026-08-10 12:03 UTC|newest]
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