CVE-2026-98648: s390/uv: Prevent potential out-of-bounds read

CVE-2026-98648: s390/uv: Prevent potential out-of-bounds read

[Greg Kroah-Hartman]

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

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

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

s390/uv: Prevent potential out-of-bounds read

When the system has more than 85 secrets, the uv_secret_list struct
array only holds up to 85 items per page, resulting in an out of bounds
read in find_secret_in_page if the targeted secret is in the next page
or not stored at all.

Fix this by looping over the number of stored secrets which is the
per sub-list count of stored secrets and not the overall count.

The Linux kernel CVE team has assigned CVE-2026-98648 to this issue.


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

	Issue introduced in 6.13 with commit 7c9137af2042e0d67aae0ccd84afc8ffc4b0d95d and fixed in 6.18.55 with commit 04bb5b2eb9f1d56110f14d3a4e31fa2c65fb026f
	Issue introduced in 6.13 with commit 7c9137af2042e0d67aae0ccd84afc8ffc4b0d95d and fixed in 7.2.9 with commit 116bba758533a139bbede8d717a1371bd6d890f6
	Issue introduced in 6.13 with commit 7c9137af2042e0d67aae0ccd84afc8ffc4b0d95d and fixed in 7.3-rc5 with commit f47190b08b71e8482072978373ee88cb2dfbdaf4

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-2026-98648
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/kernel/uv.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/04bb5b2eb9f1d56110f14d3a4e31fa2c65fb026f
	https://git.kernel.org/stable/c/116bba758533a139bbede8d717a1371bd6d890f6
	https://git.kernel.org/stable/c/f47190b08b71e8482072978373ee88cb2dfbdaf4