Cloudanix VulnDB

CVE-2026-98752

None

CVSS

—

EPSS

0.2%

Published

Oct 18, 2026

CISA due date

—

Cloudanix analysis

Next patch cycle SSVC: Track

A flaw in how the system handles device disconnections can cause crashes or errors if multiple actions happen at the same time.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Privilege Gain
Component
OS kernel
Class
Race Condition
Remediation
Patch
Effort
Medium
Patch risk
Low

What it actually does

A race condition in tty_port_tty_vhangup() and tty_port_hangup() allows concurrent hangup operations to return before the port is fully shut down, leading to use-after-free and NULL pointer dereference vulnerabilities in subsequent ioctl calls and asynchronous hangup processing.

Why it matters to the business

Systems running affected Linux kernels may experience crashes or unpredictable behavior during device deregistration or carrier loss events, potentially leading to denial of service. With low exploitability indicators and no known in-the-wild exploitation, immediate risk is minimal but kernel stability is impacted.

How an attack unfolds

An attacker with local access triggers concurrent hangup operations on a tty port, such as through racing ioctls or carrier loss events, exploiting the lack of serialization to access freed memory or null pointers during port shutdown.

How to fix it

Update to a Linux kernel version that includes the fix for the race condition in tty port handling. Apply the patch that adds missing serialization to tty_port_tty_vhangup() and tty_port_hangup().

How to confirm the fix worked

Verify the kernel source includes the added serialization logic in tty_port_tty_vhangup() and confirm no race conditions occur under concurrent hangup tests. Check kernel version against fixed releases.

Typical attack path

  1. Gain local access to the system
  2. Identify tty ports in use
  3. Craft concurrent hangup operations via ioctls or signal carrier loss
  4. Trigger use-after-free or null dereference

How to detect it

Look for kernel oops or panic logs related to tty port operations, use-after-free warnings in dmesg, or NULL pointer dereference crashes during device removal or carrier loss events.

What your security team should do

  • Monitor for kernel updates addressing tty port races
  • Test patches in staging environments before production deployment
  • Review local access controls to limit potential exploit vectors

The record

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 packages

Ecosystem Package Introduced Fixed