CVE-2026-72164: ocfs2: avoid moving extents to occupied clusters

CVE-2026-72164: ocfs2: avoid moving extents to occupied clusters

[Greg Kroah-Hartman]

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

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

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

ocfs2: avoid moving extents to occupied clusters

For non-auto OCFS2_IOC_MOVE_EXT operations, userspace supplies a physical
me_goal.  ocfs2_move_extent() initializes new_phys_cpos from that goal and
expects ocfs2_probe_alloc_group() to replace it with a free run in the
target block group.

The probe currently leaves *phys_cpos unchanged if the scan reaches the
end of the group without finding a free run.  An occupied goal at the last
bit can therefore survive the probe and be passed to
__ocfs2_move_extent(), which copies file data into a cluster still owned
by another inode before the bitmap is updated.

When the probe does find a free run, it also subtracts move_len from the
ending bit.  The start of an N-bit run ending at i is i - N + 1, so the
current calculation can report the bit immediately before the free run.

Clear *phys_cpos before scanning and use the correct free-run start. 
Callers already treat a zero result as -ENOSPC, so failed probes no longer
continue with an occupied caller-controlled goal.

The Linux kernel CVE team has assigned CVE-2026-72164 to this issue.


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

	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 5.10.261 with commit 3112afebf2a76e522fbaabcbb0c47aafbdc35932
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 5.15.212 with commit 35486b291b8fbde6c4d0b1c79e565c6260d3329d
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 6.1.178 with commit 19f7b04924b20b81dabbeed19d5542792ba5b6d6
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 6.6.145 with commit e281d892ce5870a50fdc718cb3bfc3dd5b62c728
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 6.12.97 with commit 0d0c5c17b18bdbc592ac26ab4d1de7e3dbf9be1e
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 6.18.40 with commit d5d5a21fb33cd9b963aea99da81e4dacd452cd95
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 7.1.5 with commit 4d1953d3aeb4a7f6623083e1839068ee1c157db2
	Issue introduced in 3.0 with commit e6b5859cccfa0fec02f3c5b1069481efc7186f47 and fixed in 7.2-rc1 with commit 22920541c35a9f23f219038ba5874c843a7c4419

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-2026-72164
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/ocfs2/move_extents.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/3112afebf2a76e522fbaabcbb0c47aafbdc35932
	https://git.kernel.org/stable/c/35486b291b8fbde6c4d0b1c79e565c6260d3329d
	https://git.kernel.org/stable/c/19f7b04924b20b81dabbeed19d5542792ba5b6d6
	https://git.kernel.org/stable/c/e281d892ce5870a50fdc718cb3bfc3dd5b62c728
	https://git.kernel.org/stable/c/0d0c5c17b18bdbc592ac26ab4d1de7e3dbf9be1e
	https://git.kernel.org/stable/c/d5d5a21fb33cd9b963aea99da81e4dacd452cd95
	https://git.kernel.org/stable/c/4d1953d3aeb4a7f6623083e1839068ee1c157db2
	https://git.kernel.org/stable/c/22920541c35a9f23f219038ba5874c843a7c4419