Subject: CVE-2021-46932: Input: appletouch - initialize work before device registration

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

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

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

Input: appletouch - initialize work before device registration

Syzbot has reported warning in __flush_work(). This warning is caused by
work->func == NULL, which means missing work initialization.

This may happen, since input_dev->close() calls
cancel_work_sync(&dev->work), but dev->work initalization happens _after_
input_register_device() call.

So this patch moves dev->work initialization before registering input
device

The Linux kernel CVE team has assigned CVE-2021-46932 to this issue.

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

	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 4.4.298 with commit d2cb2bf39a6d
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 4.9.296 with commit d1962f263a17
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 4.14.261 with commit 292d2ac61fb0
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 4.19.224 with commit a02e1404e278
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 5.4.170 with commit 975774ea7528
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 5.10.90 with commit 9f329d0d6c91
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 5.15.13 with commit e79ff8c68acb
	Issue introduced in 2.6.23 with commit 5a6eb676d3bc and fixed in 5.16 with commit 9f3ccdc3f6ef

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-2021-46932
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/input/mouse/appletouch.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/d2cb2bf39a6d17ef4bdc0e59c1a35cf5751ad8f4
	https://git.kernel.org/stable/c/d1962f263a176f493400b8f91bfbf2bfedce951e
	https://git.kernel.org/stable/c/292d2ac61fb0d9276a0f7b7ce4f50426f2a1c99f
	https://git.kernel.org/stable/c/a02e1404e27855089d2b0a0acc4652c2ce65fe46
	https://git.kernel.org/stable/c/975774ea7528b489930b76a77ffc4d5379b95ff2
	https://git.kernel.org/stable/c/9f329d0d6c91142cf0ad08d23c72dd195db2633c
	https://git.kernel.org/stable/c/e79ff8c68acb1eddf709d3ac84716868f2a91012
	https://git.kernel.org/stable/c/9f3ccdc3f6ef10084ceb3a47df0961bec6196fd0