From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-cve-announce@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@kernel.org>
Subject: CVE-2026-46243: smb: client: reject userspace cifs.spnego descriptions
Date: Mon, 1 Jun 2026 18:21:41 +0200 [thread overview]
Message-ID: <2026060140-CVE-2026-46243-3d1c@gregkh> (raw)
From: Greg Kroah-Hartman <gregkh@kernel.org>
Description
===========
In the Linux kernel, the following vulnerability has been resolved:
smb: client: reject userspace cifs.spnego descriptions
cifs.spnego key descriptions contain authority-bearing fields such as
pid, uid, creduid, and upcall_target that cifs.upcall treats as
kernel-originating inputs. However, userspace can also create keys of
this type through request_key(2) or add_key(2), allowing those fields to
be supplied without CIFS origin.
Only accept cifs.spnego descriptions while CIFS is using its private
spnego_cred to request the key.
The Linux kernel CVE team has assigned CVE-2026-46243 to this issue.
Affected and fixed versions
===========================
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 5.10.258 with commit 7713bd320ed4fc3d08a227cd8e41242219a16981
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 5.15.209 with commit 9544559e59438a4b609b2fdfa0763d8360572824
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 6.1.175 with commit cf20038657d6d4974349556a34e08fe0490bebbc
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 6.6.142 with commit 2035acfb17221729b1b8ac335e941868a04ca079
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 6.12.92 with commit a3bbda6502a9398b816fa2e71c9a3f955f58013d
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 6.18.34 with commit 91f89c1d83e80417629791fcef6af8140d7d01c8
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 7.0.11 with commit 0aece6685fc80a8de492688ca2315fb86ec379c7
Issue introduced in 2.6.24 with commit f1d662a7d5e5322e583aad6b3cfec03d8f27b435 and fixed in 7.1-rc5 with commit 3da1fdf4efbc490041eb4f836bf596201203f8f2
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-2026-46243
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:
fs/smb/client/cifs_spnego.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/7713bd320ed4fc3d08a227cd8e41242219a16981
https://git.kernel.org/stable/c/9544559e59438a4b609b2fdfa0763d8360572824
https://git.kernel.org/stable/c/cf20038657d6d4974349556a34e08fe0490bebbc
https://git.kernel.org/stable/c/2035acfb17221729b1b8ac335e941868a04ca079
https://git.kernel.org/stable/c/a3bbda6502a9398b816fa2e71c9a3f955f58013d
https://git.kernel.org/stable/c/91f89c1d83e80417629791fcef6af8140d7d01c8
https://git.kernel.org/stable/c/0aece6685fc80a8de492688ca2315fb86ec379c7
https://git.kernel.org/stable/c/3da1fdf4efbc490041eb4f836bf596201203f8f2
reply other threads:[~2026-06-01 16:22 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2026060140-CVE-2026-46243-3d1c@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=cve@kernel.org \
--cc=gregkh@kernel.org \
--cc=linux-cve-announce@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox