Subject: CVE-2021-47474: comedi: vmk80xx: fix bulk-buffer overflow

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

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

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

comedi: vmk80xx: fix bulk-buffer overflow

The driver is using endpoint-sized buffers but must not assume that the
tx and rx buffers are of equal size or a malicious device could overflow
the slab-allocated receive buffer when doing bulk transfers.

The Linux kernel CVE team has assigned CVE-2021-47474 to this issue.

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

	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 4.4.292 with commit e0e6a63fd97a
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 4.9.290 with commit 7cfb35db6077
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 4.14.255 with commit 0866dcaa828c
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 4.19.217 with commit 063f576c43d5
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 5.4.159 with commit 1ae4715121a5
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 5.10.79 with commit b7fd7f3387f0
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 5.14.18 with commit 7b0e35618932
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 5.15.2 with commit 47b4636ebdbe
	Issue introduced in 2.6.31 with commit 985cafccbf9b and fixed in 5.16 with commit 78cdfd62bd54

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-2021-47474
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/comedi/drivers/vmk80xx.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/e0e6a63fd97ad95fe05dfd77268a1952551e11a7
	https://git.kernel.org/stable/c/7cfb35db607760698d299fd1cf7402dfa8f09973
	https://git.kernel.org/stable/c/0866dcaa828c21bc2f94dac00e086078f11b5772
	https://git.kernel.org/stable/c/063f576c43d589a4c153554b681d32b3f8317c7b
	https://git.kernel.org/stable/c/1ae4715121a57bc6fa29fd992127b01907f2f993
	https://git.kernel.org/stable/c/b7fd7f3387f070215e6be341e68eb5c087eeecc0
	https://git.kernel.org/stable/c/7b0e356189327287d0eb98ec081bd6dd97068cd3
	https://git.kernel.org/stable/c/47b4636ebdbeba2044b3db937c4d2b6a4fe3d0f2
	https://git.kernel.org/stable/c/78cdfd62bd54af615fba9e3ca1ba35de39d3871d