CVE-2026-97486: hpfs: handle set_blocksize failures

CVE-2026-97486: hpfs: handle set_blocksize failures

[Greg Kroah-Hartman]

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

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

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

hpfs: handle set_blocksize failures

hpfs uses buffer_heads, which don't handle block size > PAGE_SIZE well.
Without this, mounting will hit the

        BUG_ON(offset >= folio_size(folio));

in folio_set_bh on the first __bread_gfp call.

The Linux kernel CVE team has assigned CVE-2026-97486 to this issue.


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

	Fixed in 6.12.111 with commit fc79fcc78cb771f2a803e52149cac5ca9050fd05
	Fixed in 6.18.53 with commit f27e21cf3c0446a3536ea9b588a78a46b0a2cb66
	Fixed in 7.2 with commit a405996f23e04942aad064ab8d50c55827482872

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-2026-97486
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:
	fs/hpfs/super.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/fc79fcc78cb771f2a803e52149cac5ca9050fd05
	https://git.kernel.org/stable/c/f27e21cf3c0446a3536ea9b588a78a46b0a2cb66
	https://git.kernel.org/stable/c/a405996f23e04942aad064ab8d50c55827482872