CVE-2026-98748

What the bug is

brcmuart_handle_irq() starts priv->hrt to work around a receive-timeout quirk of the 8250 core when hardware flow control is enabled; the timer callback brcmuart_hrtimer_func() dereferences priv. brcmuart_remove() cancels the hrtimer before it unregisters the port, so a receive-timeout interrupt that arrives in between re-arms the timer. After devm frees priv, the callback runs on freed memory. Unregister the port before cancelling the hrtimer. serial8250_unregister_port() shuts the port down and frees its IRQ, so brcmuart_handle_irq() can no longer restart the timer, and the final hrtimer_cancel() drains any timer that was armed before or during the unregister. This issue was found by an in-house static analysis tool.

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/8250/8250_bcm7271.c

What this is

BROADCOM BRCMSTB UART DRIVERMAINTAINERS section matched on drivers/tty/serial/8250/8250_bcm7271.c · linux-serial@vger.kernel.org · Maintained

Check it on the machine

grep -wE 'CONFIG_SERIAL_8250|CONFIG_SERIAL_8250_BCM7271' /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 does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sidn

n

not enabled on any flavour - this release does not build the code

Build switches

CONFIG_SERIAL_8250, CONFIG_SERIAL_8250_BCM7271

Reads as

all on means the file is compiled; any one off means it is not.

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

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
5.13	6.12.113	f5ce06e648d7
5.13	6.18.56	e32440fa536a
5.13	7.2.10	0794ba533275
5.13	7.3	189b9dc8c96e