Subject: CVE-2022-48798: s390/cio: verify the driver availability for path_event call

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

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

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

s390/cio: verify the driver availability for path_event call

If no driver is attached to a device or the driver does not provide the
path_event function, an FCES path-event on this device could end up in a
kernel-panic. Verify the driver availability before the path_event
function call.

The Linux kernel CVE team has assigned CVE-2022-48798 to this issue.

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

	Issue introduced in 5.11 with commit 32ef938815c1 and fixed in 5.15.24 with commit fe990b7bf6ac
	Issue introduced in 5.11 with commit 32ef938815c1 and fixed in 5.16.10 with commit a0619027f115
	Issue introduced in 5.11 with commit 32ef938815c1 and fixed in 5.17 with commit dd9cb842fa9d

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-2022-48798
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/s390/cio/device.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/fe990b7bf6ac93f1d850d076b8f0e758268aa4ab
	https://git.kernel.org/stable/c/a0619027f11590b2070624297530c34dc7f91bcd
	https://git.kernel.org/stable/c/dd9cb842fa9d90653a9b48aba52f89c069f3bc50