CVE-2025-38448 usb: gadget: u_serial: Fix race condition in TTY wakeup

What is CVE-2025-38448?

CVE-2025-38448 is a medium-severity vulnerability in Debian Debian Linux, published on 25 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

usb: gadget: u_serial: Fix race condition in TTY wakeup

A race condition occurs when gs_start_io() calls either gs_start_rx() or gs_start_tx(), as those functions briefly drop the port_lock for usb_ep_queue(). This allows gs_close() and gserial_disconnect() to clear port.tty and port_usb, respectively.

Use the null-safe TTY Port helper function to wake up TTY.

Example CPU1: CPU2: gserial_connect() // lock gs_close() // await lock gs_start_rx() // unlock usb_ep_queue() gs_close() // lock, reset port.tty and unlock gs_start_rx() // lock tty_wakeup() // NPE

Weakness: CWE-362

Which versions are affected by CVE-2025-38448?

It affects 2 products.

Products include Debian Debian Linux, Linux kernel.

How do I fix CVE-2025-38448?

Apply the vendor's patch.

Is CVE-2025-38448 being exploited?

There is no known exploitation of CVE-2025-38448 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-65690, BELL-CVE-2025-38448, DEBIAN-CVE-2025-38448, GHSA-x2v9-p3x8-4hp5, ROOT-OS-DEBIAN-11-CVE-2025-38448, ROOT-OS-DEBIAN-12-CVE-2025-38448 and 3 more.