CVE-2026-90384

What the bug is

A sashiko review of an unrelated patch points out that the folio batch mechanism used for iomap zero range fails to release the batch in a couple error scenarios. If either calls to ->iomap_end() or ->iomap_begin() fail, the direct return paths bypass the batch cleanup. The ->iomap_end() case is not a practical issue at the moment because there is no user of the mechanism that returns an error from this path. The ->iomap_begin() case is theoretically possible because XFS can invoke the fill helper and error out at various points thereafter. This subtly complicates things because XFS does not transfer iomap_flags to the iomap data structure in the error path. To deal with both of these issues, first make sure to invoke the cleanup helper in the error path for either fs callback. Second, update the helper to clear the flag unconditionally and release the batch so long as it is populated. This more clearly delineates the purpose of the flag to control the I/O path and not necessarily the status of the fbatch, so add a comment around this as well.

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/iomap/iter.c

What this is

FILESYSTEMS [IOMAP]MAINTAINERS section matched on fs/iomap/ · linux-xfs@vger.kernel.org · Supported

Check it on the machine

grep -w CONFIG_FS_IOMAP /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.

Show whether Debian builds this, per release

Debian builds this code. Every release below compiles the affected file into the kernels it ships.

• bookworm, trixie, forky, sidy

y

built into the kernel image on every flavour - only a patch removes it

Build switch

CONFIG_FS_IOMAP

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

0.21%, higher than 10.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

fs/iomap

Upstream fixes

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

Introduced	Fixed in	Commit
6.19	7.2.6	34470cc3a8e6
6.19	7.3	31e3d833d522