CVE-2026-68325: iommu/amd: Bound the early ACPI HID map

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

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

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

iommu/amd: Bound the early ACPI HID map

The ivrs_acpihid command-line parser appends entries to a fixed
four-element early_acpihid_map array. Unlike the sibling IOAPIC and HPET
parsers, it does not reject a fifth entry before incrementing the map size.

Check the capacity at the common found label before parsing the HID and
UID or writing the entry.

The Linux kernel CVE team has assigned CVE-2026-68325 to this issue.


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

	Issue introduced in 4.7 with commit ca3bf5d47cec8b7614bcb2e9132c40081d6d81db and fixed in 6.6.148 with commit 1e31d2394e0db69541b1591d46c5ad6431c81db3
	Issue introduced in 4.7 with commit ca3bf5d47cec8b7614bcb2e9132c40081d6d81db and fixed in 6.12.101 with commit abe5d7962f09adada9c4fb25b816dddd3f97c55d
	Issue introduced in 4.7 with commit ca3bf5d47cec8b7614bcb2e9132c40081d6d81db and fixed in 6.18.42 with commit e5ebe8544df1a1c3611739a8622156094fe470df
	Issue introduced in 4.7 with commit ca3bf5d47cec8b7614bcb2e9132c40081d6d81db and fixed in 7.1.6 with commit 030a8e84f8f1b6e96f469c84a13a225c3699910b
	Issue introduced in 4.7 with commit ca3bf5d47cec8b7614bcb2e9132c40081d6d81db and fixed in 7.2-rc5 with commit fb80117fddb5b477218dc99bb53911b72c3847f8

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-2026-68325
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/iommu/amd/init.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/1e31d2394e0db69541b1591d46c5ad6431c81db3
	https://git.kernel.org/stable/c/abe5d7962f09adada9c4fb25b816dddd3f97c55d
	https://git.kernel.org/stable/c/e5ebe8544df1a1c3611739a8622156094fe470df
	https://git.kernel.org/stable/c/030a8e84f8f1b6e96f469c84a13a225c3699910b
	https://git.kernel.org/stable/c/fb80117fddb5b477218dc99bb53911b72c3847f8