{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-19T13:05:39.597","vulnerabilities":[{"cve":{"id":"CVE-2025-21823","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2025-02-27T20:16:04.793","lastModified":"2025-11-03T21:19:12.880","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: Drop unmanaged ELP metric worker\n\nThe ELP worker needs to calculate new metric values for all neighbors\n\"reachable\" over an interface. Some of the used metric sources require\nlocks which might need to sleep. This sleep is incompatible with the RCU\nlist iterator used for the recorded neighbors. The initial approach to work\naround of this problem was to queue another work item per neighbor and then\nrun this in a new context.\n\nEven when this solved the RCU vs might_sleep() conflict, it has a major\nproblems: Nothing was stopping the work item in case it is not needed\nanymore - for example because one of the related interfaces was removed or\nthe batman-adv module was unloaded - resulting in potential invalid memory\naccesses.\n\nDirectly canceling the metric worker also has various problems:\n\n* cancel_work_sync for a to-be-deactivated interface is called with\n  rtnl_lock held. But the code in the ELP metric worker also tries to use\n  rtnl_lock() - which will never return in this case. This also means that\n  cancel_work_sync would never return because it is waiting for the worker\n  to finish.\n* iterating over the neighbor list for the to-be-deactivated interface is\n  currently done using the RCU specific methods. Which means that it is\n  possible to miss items when iterating over it without the associated\n  spinlock - a behaviour which is acceptable for a periodic metric check\n  but not for a cleanup routine (which must \"stop\" all still running\n  workers)\n\nThe better approch is to get rid of the per interface neighbor metric\nworker and handle everything in the interface worker. The original problems\nare solved by:\n\n* creating a list of neighbors which require new metric information inside\n  the RCU protected context, gathering the metric according to the new list\n  outside the RCU protected context\n* only use rcu_trylock inside metric gathering code to avoid a deadlock\n  when the cancel_delayed_work_sync is called in the interface removal code\n  (which is called with the rtnl_lock held)"},{"lang":"es","value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: batman-adv: eliminar un trabajador de métricas ELP no administrado El trabajador ELP necesita calcular nuevos valores de métricas para todos los vecinos \"alcanzables\" a través de una interfaz. Algunas de las fuentes de métricas utilizadas requieren bloqueos que podrían necesitar dormir. Esta suspensión es incompatible con el iterador de lista RCU utilizado para los vecinos registrados. El enfoque inicial para solucionar este problema fue poner en cola otro elemento de trabajo por vecino y luego ejecutarlo en un nuevo contexto. Incluso cuando esto resolvió el conflicto RCU vs might_sleep(), tiene un problema importante: nada detenía el elemento de trabajo en caso de que ya no fuera necesario, por ejemplo, porque se eliminó una de las interfaces relacionadas o se descargó el módulo batman-adv, lo que resultó en posibles accesos de memoria no válidos. Cancelar directamente el trabajador de métricas también tiene varios problemas: * cancel_work_sync para una interfaz que se desactivará se llama con rtnl_lock retenido. Pero el código en el trabajador de métricas ELP también intenta usar rtnl_lock() - que nunca regresará en este caso. Esto también significa que cancel_work_sync nunca regresaría porque está esperando que el trabajador termine. * iterar sobre la lista de vecinos para la interfaz que se va a desactivar se realiza actualmente utilizando los métodos específicos de RCU. Lo que significa que es posible omitir elementos al iterarla sin el spinlock asociado - un comportamiento que es aceptable para una verificación periódica de métricas pero no para una rutina de limpieza (que debe \"detener\" todos los trabajadores que aún se están ejecutando) El mejor enfoque es deshacerse del trabajador de métricas de vecinos por interfaz y manejar todo en el trabajador de interfaz. Los problemas originales se resuelven: * creando una lista de vecinos que requieren nueva información métrica dentro del contexto protegido de RCU, recopilando la métrica de acuerdo con la nueva lista fuera del contexto protegido de RCU * solo use rcu_trylock dentro del código de recopilación de métricas para evitar un bloqueo cuando se llama a cancel_delayed_work_sync en el código de eliminación de interfaz (que se llama con rtnl_lock retenido)"}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"NVD-CWE-noinfo"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"5.4.291","matchCriteriaId":"12DA8BBB-38CB-4CD1-897F-7B5EA22A779B"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.235","matchCriteriaId":"545121FA-DE31-4154-9446-C2000FB4104D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.179","matchCriteriaId":"C708062C-4E1B-465F-AE6D-C09C46400875"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.129","matchCriteriaId":"2DA5009C-C9B9-4A1D-9B96-78427E8F232C"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.79","matchCriteriaId":"B16AADE5-B2FD-4C14-B4E4-85E8EDAFE775"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.16","matchCriteriaId":"13C8DB18-FC60-425F-84E5-3EDDEC61B2FC"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.13.4","matchCriteriaId":"2A2093ED-74A9-43F9-AC72-50030F374EA4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*","matchCriteriaId":"186716B6-2B66-4BD0-852E-D48E71C0C85F"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*","matchCriteriaId":"0D3E781C-403A-498F-9DA9-ECEE50F41E75"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/0fdc3c166ac17b26014313fa2b93696354511b24","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/1c334629176c2d644befc31a20d4bf75542f7631","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/3c0e0aecb78cb2a2ca1dc701982d08fedb088dc6","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/781a06fd265a8151f7601122d9c2e985663828ff","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/8c8ecc98f5c65947b0070a24bac11e12e47cc65d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/a0019971f340ae02ba54cf1861f72da7e03e6b66","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/a7aa2317285806640c844acd4cd2cd768e395264","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/af264c2a9adc37f4bdf88ca7f3affa15d8c7de9e","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html","source":"af854a3a-2127-422b-91ae-364da2661108"}]}}]}