CVE-2026-90337

What the bug is

serial_core_add_one_port() allocates uport->tty_groups after uart_configure_port(), which may register the console. If the allocation fails, the driver unwinds the port while its console remains registered. The earlier uport->name allocation has a related failure path that leaves state->uart_port linked to a port being freed. Failslab reproduced a NULL dereference in PL011 console output and a KASAN use-after-free in i.MX console output after failed binds. Allocate the name and tty_groups before linking the port and configuring it. Reserve space for the optional driver attribute group because config_port() may populate uport->attr_group during configuration.

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

2026-09-17 (31 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.21%, higher than 10.0% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

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
3.17	6.18.57	9260a92ce90e
3.17	7.2.6	c2aec15f78b2
3.17	7.3	1a0e4fbce5d9