CVE-2026-89453: iommu/amd: Put PCI device after handling PPR faults

CVE-2026-89453: iommu/amd: Put PCI device after handling PPR faults

[Greg Kroah-Hartman]

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

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

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

iommu/amd: Put PCI device after handling PPR faults

iommu_call_iopf_notifier() looks up the requester with
pci_get_domain_bus_and_slot(), which returns a PCI device with its
reference count incremented.

Neither the successful iommu_report_device_fault() path nor the abort
path drops that reference, so every handled PPR request leaks a PCI
device reference.

This is the same ownership rule that was fixed for the old iommu_v2
ppr_notifier() path by commit 6cf0981c2233 ("iommu/amd: Fix pci device
refcount leak in ppr_notifier()"), but iommu_call_iopf_notifier() was
added later as a separate PPR/IOPF notifier path.

Drop the PCI device reference after handling the PPR entry.

The Linux kernel CVE team has assigned CVE-2026-89453 to this issue.


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

	Issue introduced in 6.10 with commit 978d626b8f1a239acc635323d731c77eae54eb61 and fixed in 6.12.109 with commit 1de4443f85e4405af00153cdf8ba73ff12a65036
	Issue introduced in 6.10 with commit 978d626b8f1a239acc635323d731c77eae54eb61 and fixed in 6.18.50 with commit cfc5c1b2caa176dfd40b873a6ff07b11da34cc3e
	Issue introduced in 6.10 with commit 978d626b8f1a239acc635323d731c77eae54eb61 and fixed in 7.2.4 with commit d1470e16c1977e6c94fadf6048deafaa4d150fec
	Issue introduced in 6.10 with commit 978d626b8f1a239acc635323d731c77eae54eb61 and fixed in 7.3-rc1 with commit af3b69b16383fbc8fe5f61b5b0150d2e41ede71f

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-2026-89453
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/ppr.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/1de4443f85e4405af00153cdf8ba73ff12a65036
	https://git.kernel.org/stable/c/cfc5c1b2caa176dfd40b873a6ff07b11da34cc3e
	https://git.kernel.org/stable/c/d1470e16c1977e6c94fadf6048deafaa4d150fec
	https://git.kernel.org/stable/c/af3b69b16383fbc8fe5f61b5b0150d2e41ede71f