CVE-2026-98474: s390/pci: Fix missing device lock in zpci_report_status()

CVE-2026-98474: s390/pci: Fix missing device lock in zpci_report_status()

[Greg Kroah-Hartman]

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

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

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

s390/pci: Fix missing device lock in zpci_report_status()

When pdev is non-NULL, zpci_report_status() accesses the device's driver.
To get a consistent state matching the recovery, the device lock needs to
be held. Do so by expanding the existing device lock critical section.

The lock only needs to be held when the pdev is non-NULL, so extract
the pdev-specific reporting into a helper function which also adds a
lockdep assertion to detect calls without the device lock held.

The Linux kernel CVE team has assigned CVE-2026-98474 to this issue.


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

	Issue introduced in 6.14 with commit 4ec6054e7321dc24ebccaa08b3af0d590f5666e6 and fixed in 6.18.55 with commit 743a8458978d13d84a1cf74bcd29b9959a75d3a0
	Issue introduced in 6.14 with commit 4ec6054e7321dc24ebccaa08b3af0d590f5666e6 and fixed in 7.2.9 with commit 1b957d5c2f737cda731cb1a1b71a7524d54538f2
	Issue introduced in 6.14 with commit 4ec6054e7321dc24ebccaa08b3af0d590f5666e6 and fixed in 7.3-rc5 with commit 0261aef4b15efcee2860ab857e5cb05e9bfa47b0

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-2026-98474
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:
	arch/s390/pci/pci_event.c
	arch/s390/pci/pci_report.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/743a8458978d13d84a1cf74bcd29b9959a75d3a0
	https://git.kernel.org/stable/c/1b957d5c2f737cda731cb1a1b71a7524d54538f2
	https://git.kernel.org/stable/c/0261aef4b15efcee2860ab857e5cb05e9bfa47b0