CVE-2022-50063

{"id": "CVE-2022-50063", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "published": "2025-06-18T11:15:35.047", "references": [{"url": "https://git.kernel.org/stable/c/4c46bb49460ee14c69629e813640d8b929e88941", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8e432f157c3edc5a97a7244c666589a438f5e4d4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: felix: suppress non-changes to the tagging protocol\n\nThe way in which dsa_tree_change_tag_proto() works is that when\ndsa_tree_notify() fails, it doesn't know whether the operation failed\nmid way in a multi-switch tree, or it failed for a single-switch tree.\nSo even though drivers need to fail cleanly in\nds->ops->change_tag_protocol(), DSA will still call dsa_tree_notify()\nagain, to restore the old tag protocol for potential switches in the\ntree where the change did succeeed (before failing for others).\n\nThis means for the felix driver that if we report an error in\nfelix_change_tag_protocol(), we'll get another call where proto_ops ==\nold_proto_ops. If we proceed to act upon that, we may do unexpected\nthings. For example, we will call dsa_tag_8021q_register() twice in a\nrow, without any dsa_tag_8021q_unregister() in between. Then we will\nactually call dsa_tag_8021q_unregister() via old_proto_ops->teardown,\nwhich (if it manages to run at all, after walking through corrupted data\nstructures) will leave the ports inoperational anyway.\n\nThe bug can be readily reproduced if we force an error while in\ntag_8021q mode; this crashes the kernel.\n\necho ocelot-8021q > /sys/class/net/eno2/dsa/tagging\necho edsa > /sys/class/net/eno2/dsa/tagging # -EPROTONOSUPPORT\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000014\nCall trace:\n vcap_entry_get+0x24/0x124\n ocelot_vcap_filter_del+0x198/0x270\n felix_tag_8021q_vlan_del+0xd4/0x21c\n dsa_switch_tag_8021q_vlan_del+0x168/0x2cc\n dsa_switch_event+0x68/0x1170\n dsa_tree_notify+0x14/0x34\n dsa_port_tag_8021q_vlan_del+0x84/0x110\n dsa_tag_8021q_unregister+0x15c/0x1c0\n felix_tag_8021q_teardown+0x16c/0x180\n felix_change_tag_protocol+0x1bc/0x230\n dsa_switch_event+0x14c/0x1170\n dsa_tree_change_tag_proto+0x118/0x1c0"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: dsa: felix: suprimir los no cambios en el protocolo de etiquetado La forma en que funciona dsa_tree_change_tag_proto() es que cuando dsa_tree_notify() falla, no sabe si la operaci\u00f3n fall\u00f3 a mitad de camino en un \u00e1rbol de m\u00faltiples conmutadores o fall\u00f3 para un \u00e1rbol de un solo conmutador. Entonces, aunque los controladores necesitan fallar limpiamente en ds->ops->change_tag_protocol(), DSA seguir\u00e1 llamando a dsa_tree_notify() nuevamente, para restaurar el antiguo protocolo de etiqueta para los conmutadores potenciales en el \u00e1rbol donde el cambio s\u00ed tuvo \u00e9xito (antes de fallar para otros). Esto significa para el controlador felix que si informamos de un error en felix_change_tag_protocol(), recibiremos otra llamada donde proto_ops == old_proto_ops. Si procedemos a actuar en consecuencia, podemos hacer cosas inesperadas. Por ejemplo, llamaremos a dsa_tag_8021q_register() dos veces seguidas, sin ejecutar dsa_tag_8021q_unregister() entre ambas. Luego, llamaremos a dsa_tag_8021q_unregister() mediante old_proto_ops->teardown, lo cual (si logra ejecutarse, tras analizar las estructuras de datos da\u00f1adas) dejar\u00e1 los puertos inoperativos. El error se puede reproducir f\u00e1cilmente si forzamos un error en modo tag_8021q; esto provoca un fallo del kernel. echo ocelot-8021q > /sys/class/net/eno2/dsa/tagging echo edsa > /sys/class/net/eno2/dsa/tagging # -EPROTONOSUPPORT No se puede controlar la desreferencia del puntero NULL del n\u00facleo en la direcci\u00f3n virtual 0000000000000014 Rastreo de llamadas: vcap_entry_get+0x24/0x124 ocelot_vcap_filter_del+0x198/0x270 felix_tag_8021q_vlan_del+0xd4/0x21c dsa_switch_tag_8021q_vlan_del+0x168/0x2cc dsa_switch_event+0x68/0x1170 dsa_tree_notify+0x14/0x34 dsa_port_tag_8021q_vlan_del+0x84/0x110 dsa_tag_8021q_unregister+0x15c/0x1c0 felix_tag_8021q_teardown+0x16c/0x180 felix_change_tag_protocol+0x1bc/0x230 dsa_switch_event+0x14c/0x1170 dsa_tree_change_tag_proto+0x118/0x1c0"}], "lastModified": "2025-11-13T17:24:26.530", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6B05B3A7-DED2-4B21-94AE-AE1F779C2A3D", "versionEndExcluding": "5.19.4", "versionStartIncluding": "5.19"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}