FKIE_CVE-2022-50220
Vulnerability from fkie_nvd - Published: 2025-06-18 11:15 - Updated: 2026-06-17 05:23
Severity
Summary
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.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/usb/usbnet.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "d2d6b530d89b0a912148018027386aa049f0a309",
"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
},
{
"lessThan": "e2a521a7dcc463c5017b4426ca0804e151faeff7",
"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
},
{
"lessThan": "7f77dcbc030c2faa6d8e8a594985eeb34018409e",
"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
},
{
"lessThan": "8b4588b8b00b299be16a35be67b331d8fdba03f3",
"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
},
{
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"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
},
{
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"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
},
{
"lessThan": "a69e617e533edddf3fa3123149900f36e0a6dc74",
"status": "affected",
"version": "23f333a2bfafba80339315b724808982a9de57d9",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/usb/usbnet.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.38"
},
{
"lessThan": "2.6.38",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.9.*",
"status": "unaffected",
"version": "4.9.326",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.14.*",
"status": "unaffected",
"version": "4.14.291",
"versionType": "semver"
},
{
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"version": "4.19.256",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"version": "5.4.211",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.137",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.61",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.18.*",
"status": "unaffected",
"version": "5.18.18",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.19.*",
"status": "unaffected",
"version": "5.19.2",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
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"negate": false,
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],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusbnet: Fix linkwatch use-after-free on disconnect\n\nusbnet uses the work usbnet_deferred_kevent() to perform tasks which may\nsleep. On disconnect, completion of the work was originally awaited in\n-\u003endo_stop(). But in 2003, that was moved to -\u003edisconnect() by historic\ncommit \"[PATCH] USB: usbnet, prevent exotic rtnl deadlock\":\n\n https://git.kernel.org/tglx/history/c/0f138bbfd83c\n\nThe change was made because back then, the kernel\u0027s workqueue\nimplementation did not allow waiting for a single work. One had to wait\nfor completion of *all* work by calling flush_scheduled_work(), and that\ncould deadlock when waiting for usbnet_deferred_kevent() with rtnl_mutex\nheld in -\u003endo_stop().\n\nThe commit solved one problem but created another: It causes a\nuse-after-free in USB Ethernet drivers aqc111.c, asix_devices.c,\nax88179_178a.c, ch9200.c and smsc75xx.c:\n\n* If the drivers receive a link change interrupt immediately before\n disconnect, they raise EVENT_LINK_RESET in their (non-sleepable)\n -\u003estatus() callback and schedule usbnet_deferred_kevent().\n* usbnet_deferred_kevent() invokes the driver\u0027s -\u003elink_reset() callback,\n which calls netif_carrier_{on,off}().\n* That in turn schedules the work linkwatch_event().\n\nBecause usbnet_deferred_kevent() is awaited after unregister_netdev(),\nnetif_carrier_{on,off}() may operate on an unregistered netdev and\nlinkwatch_event() may run after free_netdev(), causing a use-after-free.\n\nIn 2010, usbnet was changed to only wait for a single instance of\nusbnet_deferred_kevent() instead of *all* work by commit 23f333a2bfaf\n(\"drivers/net: don\u0027t use flush_scheduled_work()\").\n\nUnfortunately the commit neglected to move the wait back to\n-\u003endo_stop(). Rectify that omission at long last."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: usbnet: Se corrige el Use-After-Free de linkwatch al desconectar. usbnet usa la funci\u00f3n usbnet_deferred_kevent() para ejecutar tareas que podr\u00edan estar en estado de suspensi\u00f3n. Al desconectar, la finalizaci\u00f3n de la tarea se esperaba originalmente en -\u0026gt;ndo_stop(). Sin embargo, en 2003, esto se traslad\u00f3 a -\u0026gt;disconnect() mediante el commit hist\u00f3rica \"[PATCH] USB: usbnet, previene el bloqueo rtnl ex\u00f3tico\": https://git.kernel.org/tglx/history/c/0f138bbfd83c. Este cambio se realiz\u00f3 porque, en aquel entonces, la implementaci\u00f3n de la cola de trabajo del kernel no permit\u00eda esperar una sola tarea. Se deb\u00eda esperar la finalizaci\u00f3n de *todas* las tareas llamando a flush_scheduled_work(), lo que pod\u00eda provocar un bloqueo al esperar usbnet_deferred_kevent() con rtnl_mutex en -\u0026gt;ndo_stop(). El commit resolvi\u00f3 un problema pero cre\u00f3 otro: Provoca un uso despu\u00e9s de la liberaci\u00f3n en los controladores Ethernet USB aqc111.c, asix_devices.c, ax88179_178a.c, ch9200.c y smsc75xx.c: * Si los controladores reciben una interrupci\u00f3n de cambio de enlace inmediatamente antes de la desconexi\u00f3n, generan EVENT_LINK_RESET en su devoluci\u00f3n de llamada -\u0026gt;status() (no inactiva) y programan usbnet_deferred_kevent(). * usbnet_deferred_kevent() invoca la devoluci\u00f3n de llamada -\u0026gt;link_reset() del controlador, que llama a netif_carrier_{on,off}(). * Eso a su vez programa el trabajo linkwatch_event(). Dado que usbnet_deferred_kevent() se espera despu\u00e9s de unregister_netdev(), netif_carrier_{on,off}() puede operar en un netdev no registrado y linkwatch_event() puede ejecutarse despu\u00e9s de free_netdev(), lo que provoca un error de uso despu\u00e9s de la liberaci\u00f3n. En 2010, se modific\u00f3 la configuraci\u00f3n de usbnet para que solo esperara una instancia de usbnet_deferred_kevent() en lugar de *todo* el trabajo mediante el commit 23f333a2bfaf (\"drivers/net: no usar flush_scheduled_work()\"). Lamentablemente, el commit no retras\u00f3 la espera a -\u0026gt;ndo_stop(). Se corrigi\u00f3 esta omisi\u00f3n de una vez."
}
],
"id": "CVE-2022-50220",
"lastModified": "2026-06-17T05:23:00.390",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2025-06-18T11:15:52.973",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/135199a2edd459d2b123144efcd7f9bcd95128e4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"url": "https://git.kernel.org/stable/c/635fd8953e4309b54ca6a81bed1d4a87668694f4"
},
{
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"url": "https://git.kernel.org/stable/c/7f77dcbc030c2faa6d8e8a594985eeb34018409e"
},
{
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"tags": [
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"url": "https://git.kernel.org/stable/c/8b4588b8b00b299be16a35be67b331d8fdba03f3"
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{
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{
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"url": "https://git.kernel.org/stable/c/d2d6b530d89b0a912148018027386aa049f0a309"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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"url": "https://git.kernel.org/stable/c/d49bb8cf9bfaa06aa527eb30f1a52a071da2e32f"
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{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"url": "https://git.kernel.org/stable/c/db3b738ae5f726204876f4303c49cfdf4311403f"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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],
"url": "https://git.kernel.org/stable/c/e2a521a7dcc463c5017b4426ca0804e151faeff7"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-416"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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