data built 2026-10-19T13:16:53Z

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CVE-2026-98587

firewire: cdev: fix back-transition for iso_resource_auto client resource

Published 2026-10-18 (today) by the Linux kernel CNA. Subsystem drivers/firewire. Debian urgency: unimportant.

What to do, per Debian release

Debian's own status for CVE-2026-98587 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source

ReleaseStatus VersionWhat this means
Debian 12bookwormnot affected6.1.190-1Nothing to do. bookworm never shipped the vulnerable code.
Debian 13trixienot affected6.12.113-1Nothing to do. trixie never shipped the vulnerable code.
Debian 14forkyfixed7.2.9-1Update the kernel and reboot. Fixed in 7.2.9-1. A running kernel keeps the old code until the machine restarts.
Debian unstablesidfixed7.2.9-1Update the kernel and reboot. Fixed in 7.2.9-1. A running kernel keeps the old code until the machine restarts.

The vulnerability

What the bug is

The todo member of iso_resource_auto structure represents the state of the client resource and normally transitions in the following order: ISO_RES_AUTO_ALLOC -> ISO_RES_AUTO_REALLOC -> ISO_RES_AUTO_DEALLOC However, concurrent access from the work item and the file descriptor release function can cause the state to transition backwards from ISO_RES_AUTO_DEALLOC to ISO_RES_AUTO_REALLOC. Prevent the back-transition by checking the current state before updating it in the work item.

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.

drivers/firewire/core-cdev.c

What this is
FIREWIRE SUBSYSTEMMAINTAINERS section matched on drivers/firewire/ · linux1394-devel@lists.sourceforge.net · Maintained
Kernel module
firewire_core

Check it on the machine

grep -w CONFIG_FIREWIRE /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 firewire_core

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.

  • bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
  • trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi
  • 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_FIREWIRE

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
2026-10-18 (today)source
CVSS
no vector published, unrated
Attack vector
not published
EPSS
not scored
CISA KEV
not listedthe KEV catalogue
Debian urgency
unimportantsource
Subsystem
drivers/firewire

Upstream fixes

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

IntroducedFixed inCommit
7.27.2.9ee1df60a0d0e
7.27.3c6b51091caff

Why the CNA scored it this way

The kernel CNA published no CVSS vector and no reasoning for CVE-2026-98587, which is why it is shown as unrated rather than given an invented score. 6,405 of the 20,413 CVEs here carry reasoning; this is not one of them.