CVE-2026-72011: s390/diag: Add missing array_index_nospec() call to memtop_get_page_count()

CVE-2026-72011: s390/diag: Add missing array_index_nospec() call to memtop_get_page_count()

[Greg Kroah-Hartman]

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

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

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

s390/diag: Add missing array_index_nospec() call to memtop_get_page_count()

'level' is user space controlled and used to read from an array. Add the
missing array_index_nospec() call to prevent speculative execution.

The Linux kernel CVE team has assigned CVE-2026-72011 to this issue.


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

	Issue introduced in 6.14 with commit 0d30871739ab433e114b0058f08b6b1c7b816f7e and fixed in 6.18.40 with commit c6b4d454865a81ceea1422243aaaedc363b6f713
	Issue introduced in 6.14 with commit 0d30871739ab433e114b0058f08b6b1c7b816f7e and fixed in 7.1.5 with commit 83fe36f81200b7a85f8efe0a68a4e58be84d5f64
	Issue introduced in 6.14 with commit 0d30871739ab433e114b0058f08b6b1c7b816f7e and fixed in 7.2-rc3 with commit b7577fe4c47a31ca7c99714c53244a44af03cdfe

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-2026-72011
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/diag/diag310.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/c6b4d454865a81ceea1422243aaaedc363b6f713
	https://git.kernel.org/stable/c/83fe36f81200b7a85f8efe0a68a4e58be84d5f64
	https://git.kernel.org/stable/c/b7577fe4c47a31ca7c99714c53244a44af03cdfe