CVE-2026-98752

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

tty: port: fix tty_port_tty_vhangup() race

Drivers rely on tty_port_tty_vhangup() to synchronously hang up their ports before tearing down resources as part of deregistration (e.g. on physical disconnect).

If tty_port_tty_vhangup() races with another hangup it may however return before the port has been shut down. This is in turn can lead to use-after-free and NULL-pointer dereferences in racing ioctls (including a synchronous hangup) and in processing of racing asynchronous hangups (carrier loss).

Add the missing serialisation to tty_port_tty_vhangup() and tty_port_hangup() so that the former does not return until the port has been shut down also when there is a racing hangup.

Note that serial core does not use tty_port_hangup(), but it already holds the port mutex when clearing port->tty and shutting down the port in uart_hangup().

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 5.10.259 (+19 more)