linux-cve-announce - CVE-2023-54250: ksmbd: avoid out of bounds access in decode_preauth

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025123054-CVE-2023-54250-96bc@gregkh>
Date: Tue, 30 Dec 2025 13:20:16 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2023-54250: ksmbd: avoid out of bounds access in decode_preauth_ctxt()

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: avoid out of bounds access in decode_preauth_ctxt()

Confirm that the accessed pneg_ctxt->HashAlgorithms address sits within
the SMB request boundary; deassemble_neg_contexts() only checks that the
eight byte smb2_neg_context header + (client controlled) DataLength are
within the packet boundary, which is insufficient.

Checking for sizeof(struct smb2_preauth_neg_context) is overkill given
that the type currently assumes SMB311_SALT_SIZE bytes of trailing Salt.

The Linux kernel CVE team has assigned CVE-2023-54250 to this issue.


Affected and fixed versions
===========================

	Fixed in 5.15.145 with commit 39f5b4b313b445c980a2a295bed28228c29228ed
	Fixed in 6.1.25 with commit a2f6ded41bec1d3be643c80a5eb97f1680309001
	Fixed in 6.2.12 with commit f02edb9debbd36f44efa7567031485892c7df60d
	Fixed in 6.3 with commit e7067a446264a7514fa1cfaa4052cdb6803bc6a2

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-2023-54250
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/ksmbd/smb2pdu.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/39f5b4b313b445c980a2a295bed28228c29228ed
	https://git.kernel.org/stable/c/a2f6ded41bec1d3be643c80a5eb97f1680309001
	https://git.kernel.org/stable/c/f02edb9debbd36f44efa7567031485892c7df60d
	https://git.kernel.org/stable/c/e7067a446264a7514fa1cfaa4052cdb6803bc6a2