CVE-2026-99102: ntfs: take invalidate_lock in ntfs_setattr_size()

CVE-2026-99102: ntfs: take invalidate_lock in ntfs_setattr_size()

[Greg Kroah-Hartman]

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

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

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

ntfs: take invalidate_lock in ntfs_setattr_size()

ntfs_setattr_size() updates i_size and resizes the on-disk attribute
without holding mapping->invalidate_lock.  Page faults take the lock
shared, so a fault racing the resize can resolve a VCN against the
transient runlist state of ntfs_non_resident_attr_expand() and fail
with a spurious SIGBUS, and can interleave with the size-change
epilogue (truncate_pagecache(), i_size_write(),
pagecache_isize_extended()).

Take invalidate_lock exclusively around the whole resize after
inode_dio_wait(), matching the fallocate path and other filesystems
such as xfs, which wraps truncate in its mmaplock (= invalidate_lock).

The Linux kernel CVE team has assigned CVE-2026-99102 to this issue.


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

	Issue introduced in 7.1 with commit 9c87959601e80b39a45250e362e6ddfec17cb0fa and fixed in 7.2.13 with commit f0b0738ba95731eeafd11352c74f8b48951f67dc
	Issue introduced in 7.1 with commit 9c87959601e80b39a45250e362e6ddfec17cb0fa and fixed in 7.3 with commit 9cc5761b8f28f9cef72061094eb5e37e2cd44d97

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-2026-99102
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/ntfs/file.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/f0b0738ba95731eeafd11352c74f8b48951f67dc
	https://git.kernel.org/stable/c/9cc5761b8f28f9cef72061094eb5e37e2cd44d97