CVE-2022-48892

{"id": "CVE-2022-48892", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "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": "2024-08-21T07:15:05.420", "references": [{"url": "https://git.kernel.org/stable/c/7b5cc7fd1789ea5dbb942c9f8207b076d365badc", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/87ca4f9efbd7cc649ff43b87970888f2812945b8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b22faa21b6230d5eccd233e1b7e0026a5002b287", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-415"}, {"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/core: Fix use-after-free bug in dup_user_cpus_ptr()\n\nSince commit 07ec77a1d4e8 (\"sched: Allow task CPU affinity to be\nrestricted on asymmetric systems\"), the setting and clearing of\nuser_cpus_ptr are done under pi_lock for arm64 architecture. However,\ndup_user_cpus_ptr() accesses user_cpus_ptr without any lock\nprotection. Since sched_setaffinity() can be invoked from another\nprocess, the process being modified may be undergoing fork() at\nthe same time. When racing with the clearing of user_cpus_ptr in\n__set_cpus_allowed_ptr_locked(), it can lead to user-after-free and\npossibly double-free in arm64 kernel.\n\nCommit 8f9ea86fdf99 (\"sched: Always preserve the user requested\ncpumask\") fixes this problem as user_cpus_ptr, once set, will never\nbe cleared in a task's lifetime. However, this bug was re-introduced\nin commit 851a723e45d1 (\"sched: Always clear user_cpus_ptr in\ndo_set_cpus_allowed()\") which allows the clearing of user_cpus_ptr in\ndo_set_cpus_allowed(). This time, it will affect all arches.\n\nFix this bug by always clearing the user_cpus_ptr of the newly\ncloned/forked task before the copying process starts and check the\nuser_cpus_ptr state of the source task under pi_lock.\n\nNote to stable, this patch won't be applicable to stable releases.\nJust copy the new dup_user_cpus_ptr() function over."}, {"lang": "es", "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: sched/core: corrige el error de use-after-free en dup_user_cpus_ptr() Desde el commit 07ec77a1d4e8 (\"sched: permitir que la afinidad de la CPU de la tarea se restrinja en sistemas asim\u00e9tricos\"), la configuraci\u00f3n y La limpieza de user_cpus_ptr se realiza en pi_lock para la arquitectura arm64. Sin embargo, dup_user_cpus_ptr() accede a user_cpus_ptr sin ninguna protecci\u00f3n de bloqueo. Dado que sched_setaffinity() puede invocarse desde otro proceso, el proceso que se est\u00e1 modificando puede estar pasando por fork() al mismo tiempo. Cuando se corre con la limpieza de user_cpus_ptr en __set_cpus_allowed_ptr_locked(), puede llevar a una liberaci\u00f3n posterior del usuario y posiblemente a una liberaci\u00f3n doble en el kernel arm64. El commit 8f9ea86fdf99 (\"programaci\u00f3n: conservar siempre la m\u00e1scara de CPU solicitada por el usuario\") soluciona este problema ya que user_cpus_ptr, una vez configurado, nunca se borrar\u00e1 durante la vida de una tarea. Sin embargo, este error se reintrodujo en el commit 851a723e45d1 (\"sched: borrar siempre user_cpus_ptr en do_set_cpus_allowed()\") que permite borrar user_cpus_ptr en do_set_cpus_allowed(). Esta vez afectar\u00e1 a todos los arcos. Corrija este error borrando siempre el user_cpus_ptr de la tarea reci\u00e9n clonada/bifurcada antes de que comience el proceso de copia y verifique el estado de user_cpus_ptr de la tarea fuente en pi_lock. Nota para las versiones estables: este parche no se aplicar\u00e1 a las versiones estables. Simplemente copie la nueva funci\u00f3n dup_user_cpus_ptr()."}], "lastModified": "2024-08-29T02:35:56.343", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AF60D859-5B7E-4CFA-9318-AFEFAB130E64", "versionEndExcluding": "5.15.89", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9275C81F-AE96-4CDB-AD20-7DBD36E5D909", "versionEndExcluding": "6.1.7", "versionStartIncluding": "5.16"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}