CVE-2026-90420

What the bug is

syzbot reported a hung task in nilfs_transaction_begin(). This occurs because the cleaner ioctl falls into an infinite loop if nilfs_segctor_construct() repeatedly returns -EROFS (e.g. the device is remounted as read-only after an I/O error). Currently in nilfs_clean_segments(), if err is non-zero, it logs the error and sleeps but doesn't abort when it encounters a terminal error like -EROFS. This causes the thread to loop forever. Fix this by breaking out of the loop if nilfs_segctor_construct() returns -EROFS. This matches the behaviour in nilfs_segctor_write_out(), which also handles -EROFS.

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/nilfs2/segment.c

What this is

NILFS2 FILESYSTEMMAINTAINERS section matched on fs/nilfs2/ · linux-nilfs@vger.kernel.org · Maintained

Kernel module

nilfs2

Check it on the machine

grep -w CONFIG_NILFS2_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 nilfs2

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, sid, bookworm · linux-6.12Mnot 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_NILFS2_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

2026-09-17 (31 days 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/nilfs2

Upstream fixes

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

Introduced	Fixed in	Commit
2.6.30	5.10.270	e3e9367dae1a
2.6.30	5.15.221	217b967ad788
2.6.30	6.1.188	3bcdbdaac884
2.6.30	6.6.157	d7afca8e4efb
2.6.30	6.12.110	c07e5ad6539e
2.6.30	6.18.52	1fc6df85b495
2.6.30	7.2.6	8cea0bc78ac6
2.6.30	7.3	ce5a5ad1a833

Debian advisories