CVE-2026-43394: nfsd: Fix cred ref leak in nfsd_nl_listener_set_doit().

CVE-2026-43394: nfsd: Fix cred ref leak in nfsd_nl_listener_set_doit().

[Greg Kroah-Hartman]

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

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

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

nfsd: Fix cred ref leak in nfsd_nl_listener_set_doit().

nfsd_nl_listener_set_doit() uses get_current_cred() without
put_cred().

As we can see from other callers, svc_xprt_create_from_sa()
does not require the extra refcount.

nfsd_nl_listener_set_doit() is always in the process context,
sendmsg(), and current->cred does not go away.

Let's use current_cred() in nfsd_nl_listener_set_doit().

The Linux kernel CVE team has assigned CVE-2026-43394 to this issue.


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

	Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 6.12.78 with commit 02e87ec0bc706cb93fa47b43d18c4d10102c7d54
	Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 6.18.19 with commit 019debe5851d7355bea9ff0248cc317878924d8f
	Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 6.19.9 with commit cba413765376bb466035c9160fa3130402971e2c
	Issue introduced in 6.10 with commit 16a471177496c8e04a9793812c187a2c1a2192fa and fixed in 7.0 with commit 92978c83bb4eef55d02a6c990c01c423131eefa7

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-2026-43394
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/nfsd/nfsctl.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/02e87ec0bc706cb93fa47b43d18c4d10102c7d54
	https://git.kernel.org/stable/c/019debe5851d7355bea9ff0248cc317878924d8f
	https://git.kernel.org/stable/c/cba413765376bb466035c9160fa3130402971e2c
	https://git.kernel.org/stable/c/92978c83bb4eef55d02a6c990c01c423131eefa7