Linux Kernel up to 5.19.1 USB Ethernet Driver aqc111.c usbnet_deferred_kevent use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.7$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.19.1. The affected element is the function usbnet_deferred_kevent of the file aqc111.c of the component USB Ethernet Driver. Such manipulation leads to use after free. This vulnerability is traded as CVE-2022-50220. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.19.1. It has been rated as critical. Affected by this issue is the function usbnet_deferred_kevent of the file aqc111.c of the component USB Ethernet Driver. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: usbnet: Fix linkwatch use-after-free on disconnect usbnet uses the work usbnet_deferred_kevent() to perform tasks which may sleep. On disconnect, completion of the work was originally awaited in ->ndo_stop(). But in 2003, that was moved to ->disconnect() by historic commit "[PATCH] USB: usbnet, prevent exotic rtnl deadlock": https://git.kernel.org/tglx/history/c/0f138bbfd83c The change was made because back then, the kernel's workqueue implementation did not allow waiting for a single work. One had to wait for completion of *all* work by calling flush_scheduled_work(), and that could deadlock when waiting for usbnet_deferred_kevent() with rtnl_mutex held in ->ndo_stop(). The commit solved one problem but created another: It causes a use-after-free in USB Ethernet drivers aqc111.c, asix_devices.c, ax88179_178a.c, ch9200.c and smsc75xx.c: * If the drivers receive a link change interrupt immediately before disconnect, they raise EVENT_LINK_RESET in their (non-sleepable) ->status() callback and schedule usbnet_deferred_kevent(). * usbnet_deferred_kevent() invokes the driver's ->link_reset() callback, which calls netif_carrier_{on,off}(). * That in turn schedules the work linkwatch_event(). Because usbnet_deferred_kevent() is awaited after unregister_netdev(), netif_carrier_{on,off}() may operate on an unregistered netdev and linkwatch_event() may run after free_netdev(), causing a use-after-free. In 2010, usbnet was changed to only wait for a single instance of usbnet_deferred_kevent() instead of *all* work by commit 23f333a2bfaf ("drivers/net: don't use flush_scheduled_work()"). Unfortunately the commit neglected to move the wait back to ->ndo_stop(). Rectify that omission at long last.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2022-50220 since 06/18/2025. The exploitation is known to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 12/02/2025).

The vulnerability scanner Nessus provides a plugin with the ID 271309 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-2264)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.9.326, 4.14.291, 4.19.256, 5.4.211, 5.10.137, 5.15.61, 5.18.18 or 5.19.2 eliminates this vulnerability. Applying the patch d2d6b530d89b0a912148018027386aa049f0a309/e2a521a7dcc463c5017b4426ca0804e151faeff7/7f77dcbc030c2faa6d8e8a594985eeb34018409e/8b4588b8b00b299be16a35be67b331d8fdba03f3/135199a2edd459d2b123144efcd7f9bcd95128e4/635fd8953e4309b54ca6a81bed1d4a87668694f4/d49bb8cf9bfaa06aa527eb30f1a52a071da2e32f/db3b738ae5f726204876f4303c49cfdf4311403f/a69e617e533edddf3fa3123149900f36e0a6dc74 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 (271309), EUVD (EUVD-2022-55202) and CERT Bund (WID-SEC-2025-1350). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

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

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 271309
Nessus Name: EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-2264)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 4.9.326/4.14.291/4.19.256/5.4.211/5.10.137/5.15.61/5.18.18/5.19.2
Patch: d2d6b530d89b0a912148018027386aa049f0a309/e2a521a7dcc463c5017b4426ca0804e151faeff7/7f77dcbc030c2faa6d8e8a594985eeb34018409e/8b4588b8b00b299be16a35be67b331d8fdba03f3/135199a2edd459d2b123144efcd7f9bcd95128e4/635fd8953e4309b54ca6a81bed1d4a87668694f4/d49bb8cf9bfaa06aa527eb30f1a52a071da2e32f/db3b738ae5f726204876f4303c49cfdf4311403f/a69e617e533edddf3fa3123149900f36e0a6dc74

Timelineinfo

06/18/2025 Advisory disclosed
06/18/2025 +0 days CVE reserved
06/18/2025 +0 days VulDB entry created
12/02/2025 +167 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2022-50220 (🔒)
GCVE (CVE): GCVE-0-2022-50220
GCVE (VulDB): GCVE-100-313154
EUVD: 🔒
CERT Bund: WID-SEC-2025-1350 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 06/18/2025 15:29
Updated: 12/02/2025 10:03
Changes: 06/18/2025 15:29 (60), 07/15/2025 21:51 (1), 10/20/2025 03:59 (7), 10/25/2025 23:21 (2), 11/19/2025 18:17 (12), 12/02/2025 10:03 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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