CVE-2024-26831: net/handshake: Fix handshake_req_destroy_test1

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

net/handshake: Fix handshake_req_destroy_test1

Recently, handshake_req_destroy_test1 started failing:

Expected handshake_req_destroy_test == req, but
    handshake_req_destroy_test == 0000000000000000
    req == 0000000060f99b40
not ok 11 req_destroy works

This is because "sock_release(sock)" was replaced with "fput(filp)"
to address a memory leak. Note that sock_release() is synchronous
but fput() usually delays the final close and clean-up.

The delay is not consequential in the other cases that were changed
but handshake_req_destroy_test1 is testing that handshake_req_cancel()
followed by closing the file actually does call the ->hp_destroy
method. Thus the PTR_EQ test at the end has to be sure that the
final close is complete before it checks the pointer.

We cannot use a completion here because if ->hp_destroy is never
called (ie, there is an API bug) then the test will hang.

Reported by: Guenter Roeck <linux@roeck-us.net>

The Linux kernel CVE team has assigned CVE-2024-26831 to this issue.


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

	Issue introduced in 6.6 with commit 4a0f07d71b04 and fixed in 6.6.18 with commit d74226e03df1
	Issue introduced in 6.6 with commit 4a0f07d71b04 and fixed in 6.7.6 with commit 7f97805b8df6
	Issue introduced in 6.6 with commit 4a0f07d71b04 and fixed in 6.8 with commit 4e1d71cabb19
	Issue introduced in 6.5.6 with commit 1751e4498046

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-2024-26831
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/handshake/handshake-test.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/d74226e03df1bf19848f18344401f254345af912
	https://git.kernel.org/stable/c/7f97805b8df6e33850e225e6bd3ebd9e246920af
	https://git.kernel.org/stable/c/4e1d71cabb19ec2586827adfc60d68689c68c194