Subject: CVE-2021-47403: ipack: ipoctal: fix module reference leak

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

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

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

ipack: ipoctal: fix module reference leak

A reference to the carrier module was taken on every open but was only
released once when the final reference to the tty struct was dropped.

Fix this by taking the module reference and initialising the tty driver
data when installing the tty.

The Linux kernel CVE team has assigned CVE-2021-47403 to this issue.

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

	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 4.4.286 with commit 31398849b84e
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 4.9.285 with commit c0adb5a947de
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 4.14.249 with commit dde4c1429b97
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 4.19.209 with commit 9c5b77a7ffc9
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 5.4.151 with commit 3253c87e1e5b
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 5.10.71 with commit 7cea84867847
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 5.14.10 with commit 811178f296b1
	Issue introduced in 3.18 with commit 82a82340bab6 and fixed in 5.15 with commit bb8a4fcb2136

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-2021-47403
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/ipack/devices/ipoctal.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/31398849b84ebae0d43a1cf379cb9895597f221a
	https://git.kernel.org/stable/c/c0adb5a947dec6cff7050ec56d78ecd3916f9ce6
	https://git.kernel.org/stable/c/dde4c1429b97383689f755ce92b4ed1e84a9c92b
	https://git.kernel.org/stable/c/9c5b77a7ffc983b2429ce158b50497c5d3c86a69
	https://git.kernel.org/stable/c/3253c87e1e5bc0107aab773af2f135ebccf38666
	https://git.kernel.org/stable/c/7cea848678470daadbfdaa6a112b823c290f900c
	https://git.kernel.org/stable/c/811178f296b16af30264def74c8d2179a72d5562
	https://git.kernel.org/stable/c/bb8a4fcb2136508224c596a7e665bdba1d7c3c27