Subject: CVE-2024-27025: nbd: null check for nla_nest_start

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

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

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

nbd: null check for nla_nest_start

nla_nest_start() may fail and return NULL. Insert a check and set errno
based on other call sites within the same source code.

The Linux kernel CVE team has assigned CVE-2024-27025 to this issue.

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

	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 5.4.273 with commit 44214d744be3
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 5.10.214 with commit 4af837db0fd3
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 5.15.153 with commit 98e60b538e66
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 6.1.83 with commit 96436365e5d8
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 6.6.23 with commit b7f5aed55829
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 6.7.11 with commit e803040b368d
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 6.8.2 with commit ba6a9970ce9e
	Issue introduced in 4.12 with commit 47d902b90a32 and fixed in 6.9 with commit 31edf4bbe0ba

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-2024-27025
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/block/nbd.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/44214d744be32a4769faebba764510888f1eb19e
	https://git.kernel.org/stable/c/4af837db0fd3679fabc7b7758397090b0c06dced
	https://git.kernel.org/stable/c/98e60b538e66c90b9a856828c71d4e975ebfa797
	https://git.kernel.org/stable/c/96436365e5d80d0106ea785a4f80a58e7c9edff8
	https://git.kernel.org/stable/c/b7f5aed55829f376e4f7e5ea5b80ccdcb023e983
	https://git.kernel.org/stable/c/e803040b368d046434fbc8a91945c690332c4fcf
	https://git.kernel.org/stable/c/ba6a9970ce9e284cbc04099361c58731e308596a
	https://git.kernel.org/stable/c/31edf4bbe0ba27fd03ac7d87eb2ee3d2a231af6d