CVE-2022-49597: tcp: Fix data-races around sysctl_tcp_base_mss.

CVE-2022-49597: tcp: Fix data-races around sysctl_tcp_base_mss.

[Greg Kroah-Hartman]

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

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

tcp: Fix data-races around sysctl_tcp_base_mss.

While reading sysctl_tcp_base_mss, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

The Linux kernel CVE team has assigned CVE-2022-49597 to this issue.


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

	Issue introduced in 2.6.17 with commit 5d424d5a674f782d0659a3b66d951f412901faee and fixed in 5.4.208 with commit 30b73edc1d2459ba2c71cb58fbf84a1a6e640fbf
	Issue introduced in 2.6.17 with commit 5d424d5a674f782d0659a3b66d951f412901faee and fixed in 5.10.134 with commit 514d2254c7b8aa2d257f5ffc79f0d96be2d6bfda
	Issue introduced in 2.6.17 with commit 5d424d5a674f782d0659a3b66d951f412901faee and fixed in 5.15.58 with commit 4d7dea651b7fe0322be95054f64e3711afccc543
	Issue introduced in 2.6.17 with commit 5d424d5a674f782d0659a3b66d951f412901faee and fixed in 5.18.15 with commit 9ca18116bc16ec31b9a3ce28ea1350badfa36128
	Issue introduced in 2.6.17 with commit 5d424d5a674f782d0659a3b66d951f412901faee and fixed in 5.19 with commit 88d78bc097cd8ebc6541e93316c9d9bf651b13e8

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-2022-49597
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/ipv4/tcp_output.c
	net/ipv4/tcp_timer.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/30b73edc1d2459ba2c71cb58fbf84a1a6e640fbf
	https://git.kernel.org/stable/c/514d2254c7b8aa2d257f5ffc79f0d96be2d6bfda
	https://git.kernel.org/stable/c/4d7dea651b7fe0322be95054f64e3711afccc543
	https://git.kernel.org/stable/c/9ca18116bc16ec31b9a3ce28ea1350badfa36128
	https://git.kernel.org/stable/c/88d78bc097cd8ebc6541e93316c9d9bf651b13e8