CVE-2025-21767

{"id": "CVE-2025-21767", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "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": "2025-02-27T03:15:17.383", "references": [{"url": "https://git.kernel.org/stable/c/0fb534187d2355f6c8f995321e76d1ccd1262ac1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/60f54f0d4ea530950549a8263e6fdd70a40490a4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/6bb05a33337b2c842373857b63de5c9bf1ae2a09", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/852805b6cbdb69c298a8fc9fbe79994c95106e04", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8783ceeee797d9aa9cfe150690fb9d0bac8cc459", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cc3d79e7c806cb57d71c28a4a35e7d7fb3265faa", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d9c217fadfcff7a8df58567517d1e4253f3fd243", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"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"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-667"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nclocksource: Use migrate_disable() to avoid calling get_random_u32() in atomic context\n\nThe following bug report happened with a PREEMPT_RT kernel:\n\n BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48\n in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2012, name: kwatchdog\n preempt_count: 1, expected: 0\n RCU nest depth: 0, expected: 0\n get_random_u32+0x4f/0x110\n clocksource_verify_choose_cpus+0xab/0x1a0\n clocksource_verify_percpu.part.0+0x6b/0x330\n clocksource_watchdog_kthread+0x193/0x1a0\n\nIt is due to the fact that clocksource_verify_choose_cpus() is invoked with\npreemption disabled. This function invokes get_random_u32() to obtain\nrandom numbers for choosing CPUs. The batched_entropy_32 local lock and/or\nthe base_crng.lock spinlock in driver/char/random.c will be acquired during\nthe call. In PREEMPT_RT kernel, they are both sleeping locks and so cannot\nbe acquired in atomic context.\n\nFix this problem by using migrate_disable() to allow smp_processor_id() to\nbe reliably used without introducing atomic context. preempt_disable() is\nthen called after clocksource_verify_choose_cpus() but before the\nclocksource measurement is being run to avoid introducing unexpected\nlatency."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: clocksource: Use migrants_disable() para evitar llamar a get_random_u32() en un contexto at\u00f3mico El siguiente informe de error ocurri\u00f3 con un kernel PREEMPT_RT: ERROR: funci\u00f3n inactiva llamada desde un contexto no v\u00e1lido en kernel/locking/spinlock_rt.c:48 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2012, name: kwatchdog preempt_count: 1, expected: 0 Profundidad de anidamiento de RCU: 0, expected: 0 get_random_u32+0x4f/0x110 clocksource_verify_choose_cpus+0xab/0x1a0 clocksource_verify_percpu.part.0+0x6b/0x330 clocksource_watchdog_kthread+0x193/0x1a0 Esto se debe al hecho de que clocksource_verify_choose_cpus() se invoca con la preempci\u00f3n deshabilitada. Esta funci\u00f3n invoca get_random_u32() para obtener n\u00fameros aleatorios para elegir las CPU. El bloqueo local batched_entropy_32 y/o el spinlock base_crng.lock en driver/char/random.c se adquirir\u00e1n durante la llamada. En el kernel PREEMPT_RT, ambos son bloqueos inactivos y, por lo tanto, no se pueden adquirir en un contexto at\u00f3mico. Solucione este problema utilizando migrants_disable() para permitir que smp_processor_id() se utilice de manera confiable sin introducir un contexto at\u00f3mico. Luego, se llama a preempt_disable() despu\u00e9s de clocksource_verify_choose_cpus() pero antes de que se ejecute la medici\u00f3n de la fuente de reloj para evitar introducir una latencia inesperada."}], "lastModified": "2025-11-03T20:17:16.923", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B260687C-51FF-4C09-8771-ED58F13D241C", "versionEndExcluding": "5.10.235", "versionStartIncluding": "5.10.50"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CDB1D52E-21AB-4ECE-9119-6594F8FF3B3A", "versionEndExcluding": "5.13", "versionStartIncluding": "5.12.17"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "11FDEE06-BDA7-4B56-904B-81B7552B92EB", "versionEndExcluding": "5.15.179", "versionStartIncluding": "5.13.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2DA5009C-C9B9-4A1D-9B96-78427E8F232C", "versionEndExcluding": "6.1.129", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B16AADE5-B2FD-4C14-B4E4-85E8EDAFE775", "versionEndExcluding": "6.6.79", "versionStartIncluding": "6.2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "13C8DB18-FC60-425F-84E5-3EDDEC61B2FC", "versionEndExcluding": "6.12.16", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "2A2093ED-74A9-43F9-AC72-50030F374EA4", "versionEndExcluding": "6.13.4", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "186716B6-2B66-4BD0-852E-D48E71C0C85F"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}