CVE-2026-72159

What the bug is

On a volume mounted without OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC, a non-inline regular file with non-zero i_size and zero i_clusters is structurally malformed: the extent map declares no allocated clusters yet the size header claims content exists. Keep rejecting that shape, but express it through a shared predicate so the same invariant is available to normal inode reads and online filecheck. The same zero-cluster shape is also malformed for non-inline directories. ocfs2 directory growth allocates backing storage before advancing i_size, and ocfs2_dir_foreach_blk_el() later walks until ctx->pos reaches i_size_read(inode). A forged directory dinode with a huge i_size and no clusters would repeatedly fail on holes while advancing through the claimed size. Sparse regular files remain exempt: on sparse-alloc volumes, truncate can legitimately grow i_size without allocating clusters. System inodes and inline-data dinodes also retain their separate storage rules. Mirror the check in ocfs2_filecheck_validate_inode_block() as well. filecheck reports through its own error namespace, so malformed size/cluster state is logged as a filecheck invalid-inode result rather than via ocfs2_error(), but it must not proceed into ocfs2_populate_inode().

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

fs/ocfs2/inode.c

What this is

ORACLE CLUSTER FILESYSTEM 2 (OCFS2)MAINTAINERS section matched on fs/ocfs2/ · ocfs2-devel@lists.linux.dev · Supported

Kernel module

ocfs2

Check it on the machine

grep -w CONFIG_OCFS2_FS /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w ocfs2

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookworm, trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switch

CONFIG_OCFS2_FS

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-08-15 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.22%, higher than 11.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

fs/ocfs2

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
2.6.29	5.10.261	416d3e5f8a30
2.6.29	5.15.212	ed0f938f946f
2.6.29	6.1.178	83f6756a7b71
2.6.29	6.6.145	38c1ef7ce50e
2.6.29	6.12.97	d837068eefbc
2.6.29	6.18.40	2174c68f623b
2.6.29	7.1.5	3bfeb436d4be
2.6.29	7.2	7ebc672fab7a