CVE-2026-45862: iommu/vt-d: Flush cache for PASID table before using it

CVE-2026-45862: iommu/vt-d: Flush cache for PASID table before using it

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

iommu/vt-d: Flush cache for PASID table before using it

When writing the address of a freshly allocated zero-initialized PASID
table to a PASID directory entry, do that after the CPU cache flush for
this PASID table, not before it, to avoid the time window when this
PASID table may be already used by non-coherent IOMMU hardware while
its contents in RAM is still some random old data, not zero-initialized.

The Linux kernel CVE team has assigned CVE-2026-45862 to this issue.


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

	Issue introduced in 5.10.175 with commit 7e00b52c8cdd9d3a985d63d72ecae7bde6314883 and fixed in 5.10.252 with commit cd75e77125c8a51754ca4cd60b4ca083ed735d1d
	Issue introduced in 5.15.103 with commit 5c65f097124770c3e5b9b83ed1a8b68c119bc7b5 and fixed in 5.15.202 with commit 0616137b70e6d9a547d4b60df8e1b64e36d83661
	Issue introduced in 6.1.16 with commit 2bed9455db7cc0ab7ece6b3d846472097b52855a and fixed in 6.1.165 with commit 36990407cdd257473607e33802d00e978af2759e
	Issue introduced in 6.3 with commit 194b3348bdbb7db65375c72f3f774aee4cc6614e and fixed in 6.6.128 with commit c93f23375d8c410954b0df825e814b632fd62b9d
	Issue introduced in 6.3 with commit 194b3348bdbb7db65375c72f3f774aee4cc6614e and fixed in 6.12.75 with commit 5962c30a6f05ea1ab73f039e235bb30716243517
	Issue introduced in 6.3 with commit 194b3348bdbb7db65375c72f3f774aee4cc6614e and fixed in 6.18.14 with commit 36244dfd3853f7bf89d03b8e90d56b23ce7fbc16
	Issue introduced in 6.3 with commit 194b3348bdbb7db65375c72f3f774aee4cc6614e and fixed in 6.19.4 with commit d15cda135148ea7ba929cfdbcf208182bc29a7aa
	Issue introduced in 6.3 with commit 194b3348bdbb7db65375c72f3f774aee4cc6614e and fixed in 7.0 with commit 22d169bdd2849fe6bd18c2643742e1c02be6451c
	Issue introduced in 5.4.237 with commit 1b48c70feefc499b62670521efa002ab01e05df5
	Issue introduced in 6.2.3 with commit bc348a6cc8f92e9979fbfbb3c6b48fd51b4b1dbf

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-2026-45862
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/intel/pasid.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/cd75e77125c8a51754ca4cd60b4ca083ed735d1d
	https://git.kernel.org/stable/c/0616137b70e6d9a547d4b60df8e1b64e36d83661
	https://git.kernel.org/stable/c/36990407cdd257473607e33802d00e978af2759e
	https://git.kernel.org/stable/c/c93f23375d8c410954b0df825e814b632fd62b9d
	https://git.kernel.org/stable/c/5962c30a6f05ea1ab73f039e235bb30716243517
	https://git.kernel.org/stable/c/36244dfd3853f7bf89d03b8e90d56b23ce7fbc16
	https://git.kernel.org/stable/c/d15cda135148ea7ba929cfdbcf208182bc29a7aa
	https://git.kernel.org/stable/c/22d169bdd2849fe6bd18c2643742e1c02be6451c