CVE-2026-43440: net/mana: Null service_wq on setup error to prevent double destroy

CVE-2026-43440: net/mana: Null service_wq on setup error to prevent double destroy

[Greg Kroah-Hartman]

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

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

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

net/mana: Null service_wq on setup error to prevent double destroy

In mana_gd_setup() error path, set gc->service_wq to NULL after
destroy_workqueue() to match the cleanup in mana_gd_cleanup().
This prevents a use-after-free if the workqueue pointer is checked
after a failed setup.

The Linux kernel CVE team has assigned CVE-2026-43440 to this issue.


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

	Issue introduced in 6.18.16 with commit fa3c2f8d9152344a478abb847081c1b5f84a94f5 and fixed in 6.18.19 with commit 59489ce60d7412ed82fb1d8002faa3102dcd4916
	Issue introduced in 6.19.6 with commit a9a7c3203fdc4d4a8d8a7a3b1ed05d2bb4c6e77e and fixed in 6.19.9 with commit 6c92392602b451e3869f15ab685f8f650e942b13

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-2026-43440
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/microsoft/mana/gdma_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/59489ce60d7412ed82fb1d8002faa3102dcd4916
	https://git.kernel.org/stable/c/6c92392602b451e3869f15ab685f8f650e942b13
	https://git.kernel.org/stable/c/87c2302813abc55c46485711a678e3c312b00666