CVE-2026-98747

What the bug is

port->port_dev is NULL when no port device is installed: it is cleared on teardown, and never set if registration failed before serial_core_port_device_add(). serial_core_unregister_port() passes it straight to serial_core_get_ctrl_dev(), which dereferences it: KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] RIP: serial_core_unregister_port Call Trace: serial8250_unregister_port serial8250_remove unbind_store Return early when there is no port device, and read port->port_dev under port_mutex. Also clear port->port_dev on the serial_core_register_port() error path, where the port device has already been removed.

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/tty/serial/serial_core.c

What this is

TTY LAYER AND SERIAL DRIVERSMAINTAINERS section matched on drivers/tty/ · linux-kernel@vger.kernel.org · Supported

Kernel module

serial_base

Check it on the machine

grep -w CONFIG_SERIAL_CORE /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 serial_base

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

• bookwormy
• trixie, forky, sidb

y

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

b

built in on some flavours, a module on others

Build switch

CONFIG_SERIAL_CORE

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/tty

Upstream fixes

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

Introduced	Fixed in	Commit
6.5	7.2.10	54abbb862366
6.5	7.3	499485a67fba