Linux Kernel up to 6.16-rc4 usb gs_start_io race condition

CVSS Meta Temp Score
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CTI Interest Score
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4.5$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.16-rc4. This affects the function gs_start_io of the component usb. This manipulation causes race condition. This vulnerability appears as CVE-2025-38448. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.16-rc4. It has been declared as problematic. Affected by this vulnerability is the function gs_start_io of the component usb. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. The impact remains unknown. The summary by CVE is:

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

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2025-38448 since 04/16/2025. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 265984 (Ubuntu Pro FIPS-updates 22.04 LTS : Linux kernel (Azure FIPS) vulnerabilities (USN-7775-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.296, 5.10.240, 5.15.189, 6.1.146, 6.6.99, 6.12.39, 6.15.7 or 6.16-rc5 eliminates this vulnerability. Applying the patch 18d58a467ccf011078352d91b4d6a0108c7318e8/d43657b59f36e88289a6066f15bc9a80df5014eb/a5012673d49788f16bb4e375b002d7743eb642d9/ee8d688e2ba558f3bb8ac225113740be5f335417/c6eb4a05af3d0ba3bc4e8159287722fb9abc6359/abf3620cba68e0e51e5c21054ce4f925f75b3661/c8c80a3a35c2e3488409de2d5376ef7e662a2bf5/c529c3730bd09115684644e26bf01ecbd7e2c2c9 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (265984), EUVD (EUVD-2025-22693) and CERT Bund (WID-SEC-2025-1653). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • RESF Rocky Linux
  • Dell Avamar
  • Open Source Linux Kernel
  • Dell NetWorker
  • Dell Secure Connect Gateway

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
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Nessus ID: 265984
Nessus Name: Ubuntu Pro FIPS-updates 22.04 LTS : Linux kernel (Azure FIPS) vulnerabilities (USN-7775-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.4.296/5.10.240/5.15.189/6.1.146/6.6.99/6.12.39/6.15.7/6.16-rc5
Patch: 18d58a467ccf011078352d91b4d6a0108c7318e8/d43657b59f36e88289a6066f15bc9a80df5014eb/a5012673d49788f16bb4e375b002d7743eb642d9/ee8d688e2ba558f3bb8ac225113740be5f335417/c6eb4a05af3d0ba3bc4e8159287722fb9abc6359/abf3620cba68e0e51e5c21054ce4f925f75b3661/c8c80a3a35c2e3488409de2d5376ef7e662a2bf5/c529c3730bd09115684644e26bf01ecbd7e2c2c9

Timelineinfo

04/16/2025 CVE reserved
07/25/2025 +100 days Advisory disclosed
07/25/2025 +0 days VulDB entry created
01/03/2026 +162 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38448 (🔒)
GCVE (CVE): GCVE-0-2025-38448
GCVE (VulDB): GCVE-100-317743
EUVD: 🔒
CERT Bund: WID-SEC-2025-1653 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 07/25/2025 19:31
Updated: 01/03/2026 23:51
Changes: 07/25/2025 19:31 (58), 07/30/2025 02:00 (1), 08/22/2025 19:43 (7), 09/15/2025 05:23 (1), 09/27/2025 05:04 (2), 09/29/2025 02:13 (1), 11/02/2025 13:58 (1), 11/17/2025 06:19 (1), 12/23/2025 00:48 (10), 12/23/2025 07:07 (1), 01/03/2026 23:51 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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