CVE-2026-89452: iommu/msm: Unwind probe state on registration failure

CVE-2026-89452: iommu/msm: Unwind probe state on registration failure

[Greg Kroah-Hartman]

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

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

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

iommu/msm: Unwind probe state on registration failure

msm_iommu_probe() adds its devm-managed IOMMU object to
qcom_iommu_devices before adding the IOMMU sysfs device and registering
it with the IOMMU core.

If iommu_device_sysfs_add() fails, probe returns with the object still on
qcom_iommu_devices. The driver core then releases the devm allocation,
leaving a dangling list entry that later list walks may dereference.

If iommu_device_register() fails, the same dangling list entry remains
and the sysfs device is left registered as well.

Unwind the sysfs device and global list entry in reverse setup order on
the corresponding failure paths.

The Linux kernel CVE team has assigned CVE-2026-89452 to this issue.


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

	Issue introduced in 4.11 with commit 42df43b36163ed7d0ab13992e411093252903273 and fixed in 6.18.50 with commit f532401be9312ecd166f616bb74a65b0b4c150fa
	Issue introduced in 4.11 with commit 42df43b36163ed7d0ab13992e411093252903273 and fixed in 7.2.4 with commit 7f7074a886c4a93e3d12076ce60a510a1ebe400c
	Issue introduced in 4.11 with commit 42df43b36163ed7d0ab13992e411093252903273 and fixed in 7.3-rc1 with commit 535a200220ca2c83bc8bf54bd2cbe045d6ee70c4

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-2026-89452
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/msm_iommu.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/f532401be9312ecd166f616bb74a65b0b4c150fa
	https://git.kernel.org/stable/c/7f7074a886c4a93e3d12076ce60a510a1ebe400c
	https://git.kernel.org/stable/c/535a200220ca2c83bc8bf54bd2cbe045d6ee70c4