Subject: CVE-2023-52880: tty: n_gsm: require CAP_NET_ADMIN to attach N_GSM0710 ldisc

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

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

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

tty: n_gsm: require CAP_NET_ADMIN to attach N_GSM0710 ldisc

Any unprivileged user can attach N_GSM0710 ldisc, but it requires
CAP_NET_ADMIN to create a GSM network anyway.

Require initial namespace CAP_NET_ADMIN to do that.

The Linux kernel CVE team has assigned CVE-2023-52880 to this issue.

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

	Fixed in 4.19.312 with commit 7d303dee473b
	Fixed in 5.4.274 with commit 7a529c9023a1
	Fixed in 5.10.215 with commit ada28eb4b956
	Fixed in 5.15.155 with commit 2d154a54c58f
	Fixed in 6.1.86 with commit 2b85977977cb
	Fixed in 6.6 with commit 67c37756898a

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-2023-52880
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/tty/n_gsm.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/7d303dee473ba3529d75b63491e9963342107bed
	https://git.kernel.org/stable/c/7a529c9023a197ab3bf09bb95df32a3813f7ba58
	https://git.kernel.org/stable/c/ada28eb4b9561aab93942f3224a2e41d76fe57fa
	https://git.kernel.org/stable/c/2d154a54c58f9c8375bfbea9f7e51ba3bfb2e43a
	https://git.kernel.org/stable/c/2b85977977cbd120591b23c2450e90a5806a7167
	https://git.kernel.org/stable/c/67c37756898a5a6b2941a13ae7260c89b54e0d88