CVE-2026-74340: wifi: wcn36xx: fix OOB read from firmware count in PRINT_REG_INFO indication

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

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

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

wifi: wcn36xx: fix OOB read from firmware count in PRINT_REG_INFO indication

The firmware-controlled rsp->count field is used as the loop bound for
indexing into the flexible rsp->regs[] array without validation against
the message length. A count exceeding the actual data causes out-of-
bounds reads from the heap-allocated message buffer.

Add a check that count fits within the received message.

The Linux kernel CVE team has assigned CVE-2026-74340 to this issue.


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

	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 5.10.261 with commit 22b0b8572a64362531dd0ed499b75e16282aeb2b
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 5.15.212 with commit 3cf92b44c4fb88a5e8de8733a4494c0956606bca
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 6.1.178 with commit 0907c06dccae9e3c8d5a68eb9014beec73a36e79
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 6.6.145 with commit 64228dfc4247aca178c01e5a37af7d8dcc7a6089
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 6.12.97 with commit 23d210877968657bd07e1a517e0b516db20a1d80
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 6.18.40 with commit f03782f7f41f2afee5076a1ef08ced5649218771
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 7.1.5 with commit f987efff29a5fe45320ea5991c9d5cb98b676953
	Issue introduced in 4.11 with commit 43efa3c0f241e04862be8e6a68ff765d36cde1ba and fixed in 7.2-rc1 with commit df2187acfca6c6cca372c5d35f42394d9c270b09

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-2026-74340
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/wcn36xx/smd.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/22b0b8572a64362531dd0ed499b75e16282aeb2b
	https://git.kernel.org/stable/c/3cf92b44c4fb88a5e8de8733a4494c0956606bca
	https://git.kernel.org/stable/c/0907c06dccae9e3c8d5a68eb9014beec73a36e79
	https://git.kernel.org/stable/c/64228dfc4247aca178c01e5a37af7d8dcc7a6089
	https://git.kernel.org/stable/c/23d210877968657bd07e1a517e0b516db20a1d80
	https://git.kernel.org/stable/c/f03782f7f41f2afee5076a1ef08ced5649218771
	https://git.kernel.org/stable/c/f987efff29a5fe45320ea5991c9d5cb98b676953
	https://git.kernel.org/stable/c/df2187acfca6c6cca372c5d35f42394d9c270b09