linux-cve-announce - CVE-2025-39805: net: macb: fix unregister_netdev call order in macb

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: <2025091610-CVE-2025-39805-2871@gregkh>
Date: Tue, 16 Sep 2025 15:00:11 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-39805: net: macb: fix unregister_netdev call order in macb_remove()

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

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

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

net: macb: fix unregister_netdev call order in macb_remove()

When removing a macb device, the driver calls phy_exit() before
unregister_netdev(). This leads to a WARN from kernfs:

  ------------[ cut here ]------------
  kernfs: can not remove 'attached_dev', no directory
  WARNING: CPU: 1 PID: 27146 at fs/kernfs/dir.c:1683
  Call trace:
    kernfs_remove_by_name_ns+0xd8/0xf0
    sysfs_remove_link+0x24/0x58
    phy_detach+0x5c/0x168
    phy_disconnect+0x4c/0x70
    phylink_disconnect_phy+0x6c/0xc0 [phylink]
    macb_close+0x6c/0x170 [macb]
    ...
    macb_remove+0x60/0x168 [macb]
    platform_remove+0x5c/0x80
    ...

The warning happens because the PHY is being exited while the netdev
is still registered. The correct order is to unregister the netdev
before shutting down the PHY and cleaning up the MDIO bus.

Fix this by moving unregister_netdev() ahead of phy_exit() in
macb_remove().

The Linux kernel CVE team has assigned CVE-2025-39805 to this issue.


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

	Issue introduced in 5.18 with commit 8b73fa3ae02b2401960de41b0454c0321377b203 and fixed in 6.12.45 with commit ff0d3bad32108b57265e5b48f15327549af771d3
	Issue introduced in 5.18 with commit 8b73fa3ae02b2401960de41b0454c0321377b203 and fixed in 6.16.5 with commit 775fe690fd4a3337ad2115de2adb41b227d4dae7
	Issue introduced in 5.18 with commit 8b73fa3ae02b2401960de41b0454c0321377b203 and fixed in 6.17-rc4 with commit 01b9128c5db1b470575d07b05b67ffa3cb02ebf1

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-2025-39805
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:
	drivers/net/ethernet/cadence/macb_main.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/ff0d3bad32108b57265e5b48f15327549af771d3
	https://git.kernel.org/stable/c/775fe690fd4a3337ad2115de2adb41b227d4dae7
	https://git.kernel.org/stable/c/01b9128c5db1b470575d07b05b67ffa3cb02ebf1