CVE-2026-68351: wifi: carl9170: bound memcpy length in cmd callback to prevent OOB read

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

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

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

wifi: carl9170: bound memcpy length in cmd callback to prevent OOB read

When the firmware sends a command response with a length mismatch,
carl9170_cmd_callback() logs the mismatch and calls carl9170_restart()
but then falls through to memcpy(ar->readbuf, buffer + 4, len - 4).
Since len comes from the firmware and can exceed ar->readlen, this
copies more data than the readbuf was allocated for.

Bound the memcpy to min(len - 4, ar->readlen) so that the response
is still completed -- avoiding repeated restarts from queued garbage --
while preventing an overread past the response buffer.

The Linux kernel CVE team has assigned CVE-2026-68351 to this issue.


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

	Issue introduced in 2.6.37 with commit a84fab3cbfdc427e7d366f1cc844f27b2084c26c and fixed in 6.6.148 with commit f74e34e66379e487a09009a4f2d42470051672bd
	Issue introduced in 2.6.37 with commit a84fab3cbfdc427e7d366f1cc844f27b2084c26c and fixed in 6.12.101 with commit 500c36649f270de05a56591fcc1aaaa36687958e
	Issue introduced in 2.6.37 with commit a84fab3cbfdc427e7d366f1cc844f27b2084c26c and fixed in 6.18.42 with commit 9aee949c68dc6dccbc54333537b109c53fe2079f
	Issue introduced in 2.6.37 with commit a84fab3cbfdc427e7d366f1cc844f27b2084c26c and fixed in 7.1.6 with commit cb7a38810cf25738176dac32dec7a146b3f959cf
	Issue introduced in 2.6.37 with commit a84fab3cbfdc427e7d366f1cc844f27b2084c26c and fixed in 7.2-rc5 with commit 4cde55b2feff9504d1f993ab80e84e7ccb62791c

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-2026-68351
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/net/wireless/ath/carl9170/rx.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/f74e34e66379e487a09009a4f2d42470051672bd
	https://git.kernel.org/stable/c/500c36649f270de05a56591fcc1aaaa36687958e
	https://git.kernel.org/stable/c/9aee949c68dc6dccbc54333537b109c53fe2079f
	https://git.kernel.org/stable/c/cb7a38810cf25738176dac32dec7a146b3f959cf
	https://git.kernel.org/stable/c/4cde55b2feff9504d1f993ab80e84e7ccb62791c