CVE-2026-72066: cpu: hotplug: Bound hotplug states sysfs output

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

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

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

cpu: hotplug: Bound hotplug states sysfs output

states_show() adds CPU hotplug state names into a single sysfs buffer
using sprintf(). With enough registered states, this can write past the
end of the PAGE_SIZE buffer.

Use sysfs_emit_at() so output is bounded.

The Linux kernel CVE team has assigned CVE-2026-72066 to this issue.


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

	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 5.15.212 with commit 2408be459c70ef4250da1a9e50f5478e6b250d61
	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 6.1.178 with commit de4d3d8ae17dc8b4cf8c59436c4b7e2dc2491635
	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 6.6.145 with commit 998f66e9ce320f3433f60b948e3698b744754a46
	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 6.12.97 with commit 61a73a123ac7a7fbc57382531f8cb7092d569aba
	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 6.18.40 with commit 6cb15b81ff545840048fb0e1a6e827d560dbf367
	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 7.1.5 with commit 631d53102da9f469c96b882b770336bec095b833
	Issue introduced in 4.6 with commit 98f8cdce1db580b99fce823a48eea2cb2bdb261e and fixed in 7.2-rc1 with commit 86f436567f2516a0083b210bedc933544826a2c3

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-2026-72066
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:
	kernel/cpu.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/2408be459c70ef4250da1a9e50f5478e6b250d61
	https://git.kernel.org/stable/c/de4d3d8ae17dc8b4cf8c59436c4b7e2dc2491635
	https://git.kernel.org/stable/c/998f66e9ce320f3433f60b948e3698b744754a46
	https://git.kernel.org/stable/c/61a73a123ac7a7fbc57382531f8cb7092d569aba
	https://git.kernel.org/stable/c/6cb15b81ff545840048fb0e1a6e827d560dbf367
	https://git.kernel.org/stable/c/631d53102da9f469c96b882b770336bec095b833
	https://git.kernel.org/stable/c/86f436567f2516a0083b210bedc933544826a2c3