linux-cve-announce - CVE-2025-40103: smb: client: Fix refcount leak for cifs_sb

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: <2025103018-CVE-2025-40103-e5ae@gregkh>
Date: Thu, 30 Oct 2025 10:48:30 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-40103: smb: client: Fix refcount leak for cifs_sb_tlink

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

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

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

smb: client: Fix refcount leak for cifs_sb_tlink

Fix three refcount inconsistency issues related to `cifs_sb_tlink`.

Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be
called after successful calls to `cifs_sb_tlink()`. Three calls fail to
update refcount accordingly, leading to possible resource leaks.

The Linux kernel CVE team has assigned CVE-2025-40103 to this issue.


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

	Issue introduced in 3.7 with commit 8ceb984379462f94bdebef3288d569c6e1f912ea and fixed in 6.1.158 with commit 790282abe9d805f08618c1c24ea2529e7259b692
	Issue introduced in 3.7 with commit 8ceb984379462f94bdebef3288d569c6e1f912ea and fixed in 6.6.114 with commit d7dd034c14928306db1b46be277ae439b84dacf9
	Issue introduced in 3.7 with commit 8ceb984379462f94bdebef3288d569c6e1f912ea and fixed in 6.12.55 with commit e15605b68b490186da2ad8029c0351a9cfb0b9af
	Issue introduced in 3.7 with commit 8ceb984379462f94bdebef3288d569c6e1f912ea and fixed in 6.17.5 with commit 896bb31e1416f582503db1350cf1bd10dc64e5a6
	Issue introduced in 3.7 with commit 8ceb984379462f94bdebef3288d569c6e1f912ea and fixed in 6.18-rc2 with commit c2b77f42205ef485a647f62082c442c1cd69d3fc

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-2025-40103
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/inode.c
	fs/smb/client/smb2ops.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/790282abe9d805f08618c1c24ea2529e7259b692
	https://git.kernel.org/stable/c/d7dd034c14928306db1b46be277ae439b84dacf9
	https://git.kernel.org/stable/c/e15605b68b490186da2ad8029c0351a9cfb0b9af
	https://git.kernel.org/stable/c/896bb31e1416f582503db1350cf1bd10dc64e5a6
	https://git.kernel.org/stable/c/c2b77f42205ef485a647f62082c442c1cd69d3fc