CVE-2022-50220

{"id": "CVE-2022-50220", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "published": "2025-06-18T11:15:52.973", "references": [{"url": "https://git.kernel.org/stable/c/135199a2edd459d2b123144efcd7f9bcd95128e4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/635fd8953e4309b54ca6a81bed1d4a87668694f4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7f77dcbc030c2faa6d8e8a594985eeb34018409e", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8b4588b8b00b299be16a35be67b331d8fdba03f3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a69e617e533edddf3fa3123149900f36e0a6dc74", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d2d6b530d89b0a912148018027386aa049f0a309", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d49bb8cf9bfaa06aa527eb30f1a52a071da2e32f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/db3b738ae5f726204876f4303c49cfdf4311403f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e2a521a7dcc463c5017b4426ca0804e151faeff7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-416"}]}], "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->ndo_stop(). But in 2003, that was moved to ->disconnect() 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's 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 ->ndo_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 ->status() callback and schedule usbnet_deferred_kevent().\n* usbnet_deferred_kevent() invokes the driver's ->link_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't use flush_scheduled_work()\").\n\nUnfortunately the commit neglected to move the wait back to\n->ndo_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 ->ndo_stop(). Sin embargo, en 2003, esto se traslad\u00f3 a ->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 ->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 ->status() (no inactiva) y programan usbnet_deferred_kevent(). * usbnet_deferred_kevent() invoca la devoluci\u00f3n de llamada ->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 ->ndo_stop(). Se corrigi\u00f3 esta omisi\u00f3n de una vez."}], "lastModified": "2025-11-19T12:59:21.397", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4197D395-7363-4526-9658-190ED07AA35D", "versionEndExcluding": "4.9.326", "versionStartIncluding": "2.6.38"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3BBC7E43-6161-4F21-977C-5BB7792C6C94", "versionEndExcluding": "4.14.291", "versionStartIncluding": "4.10"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6C47CDE3-B039-4AE5-B8E4-1DC820E473FF", "versionEndExcluding": "4.19.256", "versionStartIncluding": "4.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B1C63D19-C08C-4308-A848-B2523C9275BD", "versionEndExcluding": "5.4.211", "versionStartIncluding": "4.20"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C2BF720F-C5EE-4DE2-9BDF-CE4CFBC767F4", "versionEndExcluding": "5.10.137", "versionStartIncluding": "5.5"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "51861563-7F40-460F-82CD-2D3FBDAD6618", "versionEndExcluding": "5.15.61", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5B42E453-8837-49D0-A5EF-03F818A6DC11", "versionEndExcluding": "5.18.18", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A1A2A5A5-4598-4D7E-BA07-4660398D6C8F", "versionEndExcluding": "5.19.2", "versionStartIncluding": "5.19"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}