CVE-2026-74553: hwmon: (nct6775-core) Fix number of temperature registers for NCT6116

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

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

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

hwmon: (nct6775-core) Fix number of temperature registers for NCT6116

Unlike NCT6106, NCT6116 only has three temperature registers, and with
it only three temperature source and temperature source configuration
registers. The register addresses match those of NCT6106 and can be
re-used.

The code used a separate array to list the temperature source registers
for NCT6116, but used the size of the NCT6106 register array to set
the number of registers. The NCT6106 register array provides six addresses,
while the temperature source register array for NCT6116 only provides three
addresses. This causes a KASAN report.

BUG: KASAN: global-out-of-bounds in nct6775_probe+0x936/0x46f0 [nct6775]
Read of size 2 at addr ffffffffc19561a6 by task modprobe/954
...
Call Trace:
 dump_stack+0x7d/0xa7
 print_address_description.constprop.0+0x1c/0x220
 ? __kasan_kmalloc.constprop.0+0xc9/0xd0
 ? __kmalloc_node_track_caller+0x194/0x5b0
 ? nct6775_probe+0x936/0x46f0 [nct6775]
 ? nct6775_probe+0x936/0x46f0 [nct6775]
...

Fix the problem by hard-coding the number of temperature and temperature
configuration registers to three for NCT6116. Drop the unnecessary
NCT6116_REG_TEMP_SOURCE array and re-use NCT6106_REG_TEMP_SOURCE.

The Linux kernel CVE team has assigned CVE-2026-74553 to this issue.


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

	Issue introduced in 5.4 with commit 29c7cb485b321c024dedc168bcbb04451176b163 and fixed in 6.6.151 with commit 9a87dfaa05c3c9d3a4cdb7eafc1ab4abc84f6eef
	Issue introduced in 5.4 with commit 29c7cb485b321c024dedc168bcbb04451176b163 and fixed in 6.12.103 with commit 16c45bb3d3434cfb9ea264fa52090d0823240465
	Issue introduced in 5.4 with commit 29c7cb485b321c024dedc168bcbb04451176b163 and fixed in 6.18.44 with commit a42d727dae5701deac8bb2a75effadae7d681153
	Issue introduced in 5.4 with commit 29c7cb485b321c024dedc168bcbb04451176b163 and fixed in 7.1.8 with commit a7f47f5246cd6c3199e5fb2d4109cc53e766e3f0
	Issue introduced in 5.4 with commit 29c7cb485b321c024dedc168bcbb04451176b163 and fixed in 7.2-rc6 with commit b0e8adb2ccb43009796897ced09f91636685c9d3

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-2026-74553
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/hwmon/nct6775-core.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/9a87dfaa05c3c9d3a4cdb7eafc1ab4abc84f6eef
	https://git.kernel.org/stable/c/16c45bb3d3434cfb9ea264fa52090d0823240465
	https://git.kernel.org/stable/c/a42d727dae5701deac8bb2a75effadae7d681153
	https://git.kernel.org/stable/c/a7f47f5246cd6c3199e5fb2d4109cc53e766e3f0
	https://git.kernel.org/stable/c/b0e8adb2ccb43009796897ced09f91636685c9d3