CVE-2026-74718: devlink: fix net namespace reference leak in reload

From: Greg Kroah-Hartman <[email protected]>

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

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

devlink: fix net namespace reference leak in reload

devlink_nl_reload_doit() calls devlink_netns_get(), which returns a net
with a held reference. When the requested namespace differs from the
current one and the reload action is not DRIVER_REINIT, the function
returns -EOPNOTSUPP without releasing the reference. Add the missing
put_net() on this error path.

The Linux kernel CVE team has assigned CVE-2026-74718 to this issue.


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

	Issue introduced in 6.3 with commit 2edd92570441dd33246210042dc167319a5cf7e3 and fixed in 6.6.152 with commit 7b6552e53426ea0539c667bbc5a524fdf7feae6f
	Issue introduced in 6.3 with commit 2edd92570441dd33246210042dc167319a5cf7e3 and fixed in 6.12.104 with commit bf0797b92be591ac71d7c0f610e695caca3c72c9
	Issue introduced in 6.3 with commit 2edd92570441dd33246210042dc167319a5cf7e3 and fixed in 6.18.45 with commit 7b02c6d2a3cd2cd669f5c16685779f84328ae60c
	Issue introduced in 6.3 with commit 2edd92570441dd33246210042dc167319a5cf7e3 and fixed in 7.1.9 with commit eda60c85b4f4c7d66b7141a5fe020b1a7f395341
	Issue introduced in 6.3 with commit 2edd92570441dd33246210042dc167319a5cf7e3 and fixed in 7.2 with commit 1c4dac9bf1d2ac31da63b794bdec697777cbd0fd

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-2026-74718
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:
	net/devlink/dev.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/7b6552e53426ea0539c667bbc5a524fdf7feae6f
	https://git.kernel.org/stable/c/bf0797b92be591ac71d7c0f610e695caca3c72c9
	https://git.kernel.org/stable/c/7b02c6d2a3cd2cd669f5c16685779f84328ae60c
	https://git.kernel.org/stable/c/eda60c85b4f4c7d66b7141a5fe020b1a7f395341
	https://git.kernel.org/stable/c/1c4dac9bf1d2ac31da63b794bdec697777cbd0fd