CVE-2026-43323

{"id": "CVE-2026-43323", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-43323", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-06T15:35:42.794523Z"}}], "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}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "d2fc2dcfce47a56ffd414783003cc966c742c8a9", "lessThan": "c089147074ed96ff4330739a0559394c19a3dfc8", "versionType": "git"}, {"status": "affected", "version": "99673934a89febe664e704550216638dcb2336a8", "lessThan": "87573883c30f1a8555ff720836bb6ea231058539", "versionType": "git"}, {"status": "affected", "version": "978d4fe59665c13db692ba96839f9c52d69f13f3", "lessThan": "fb61ffb3fb30a161eb5404c27fc7635e275beafd", "versionType": "git"}, {"status": "affected", "version": "b3d99f43c72b56cf7a104a364e7fb34b0702828b", "lessThan": "1319ea57529e131822bab56bf417c8edc2db9ae8", "versionType": "git"}], "programFiles": ["kernel/sched/fair.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.12.78", "lessThan": "6.12.81", "versionType": "semver"}, {"status": "affected", "version": "6.18.17", "lessThan": "6.18.22", "versionType": "semver"}, {"status": "affected", "version": "6.19.7", "lessThan": "6.19.12", "versionType": "semver"}], "programFiles": ["kernel/sched/fair.c"], "defaultStatus": "unaffected"}]}], "published": "2026-05-08T14:16:40.947", "references": [{"url": "https://git.kernel.org/stable/c/1319ea57529e131822bab56bf417c8edc2db9ae8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/87573883c30f1a8555ff720836bb6ea231058539", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c089147074ed96ff4330739a0559394c19a3dfc8", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/fb61ffb3fb30a161eb5404c27fc7635e275beafd", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/fair: Fix zero_vruntime tracking fix\n\nJohn reported that stress-ng-yield could make his machine unhappy and\nmanaged to bisect it to commit b3d99f43c72b (\"sched/fair: Fix\nzero_vruntime tracking\").\n\nThe combination of yield and that commit was specific enough to\nhypothesize the following scenario:\n\nSuppose we have 2 runnable tasks, both doing yield. Then one will be\neligible and one will not be, because the average position must be in\nbetween these two entities.\n\nTherefore, the runnable task will be eligible, and be promoted a full\nslice (all the tasks do is yield after all). This causes it to jump over\nthe other task and now the other task is eligible and current is no\nlonger. So we schedule.\n\nSince we are runnable, there is no {de,en}queue. All we have is the\n__{en,de}queue_entity() from {put_prev,set_next}_task(). But per the\nfingered commit, those two no longer move zero_vruntime.\n\nAll that moves zero_vruntime are tick and full {de,en}queue.\n\nThis means, that if the two tasks playing leapfrog can reach the\ncritical speed to reach the overflow point inside one tick's worth of\ntime, we're up a creek.\n\nAdditionally, when multiple cgroups are involved, there is no guarantee\nthe tick will in fact hit every cgroup in a timely manner. Statistically\nspeaking it will, but that same statistics does not rule out the\npossibility of one cgroup not getting a tick for a significant amount of\ntime -- however unlikely.\n\nTherefore, just like with the yield() case, force an update at the end\nof every slice. This ensures the update is never more than a single\nslice behind and the whole thing is within 2 lag bounds as per the\ncomment on entity_key()."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nsched/fair: Correcci\u00f3n del seguimiento de zero_vruntime\n\nJohn inform\u00f3 que stress-ng-yield pod\u00eda hacer que su m\u00e1quina funcionara mal y logr\u00f3 identificar la causa hasta el commit b3d99f43c72b (\u2019sched/fair: Fix zero_vruntime tracking\u2019).\n\nLa combinaci\u00f3n de yield y ese commit fue lo suficientemente espec\u00edfica como para hipotetizar el siguiente escenario:\n\nSupongamos que tenemos 2 tareas ejecutables, ambas haciendo yield. Entonces una ser\u00e1 elegible y la otra no, porque la posici\u00f3n promedio debe estar entre estas dos entidades.\n\nPor lo tanto, la tarea ejecutable ser\u00e1 elegible y ser\u00e1 promovida una porci\u00f3n completa (despu\u00e9s de todo, todo lo que hacen las tareas es yield). Esto hace que salte sobre la otra tarea y ahora la otra tarea es elegible y la actual ya no lo es. As\u00ed que planificamos.\n\nDado que somos ejecutables, no hay {de,en}queue. Todo lo que tenemos es el __{en,de}queue_entity() de {put_prev,set_next}_task(). Pero seg\u00fan el commit se\u00f1alado, esos dos ya no mueven zero_vruntime.\n\nTodo lo que mueve zero_vruntime son el tick y el {de,en}queue completo.\n\nEsto significa que, si las dos tareas que juegan a la rayuela pueden alcanzar la velocidad cr\u00edtica para llegar al punto de desbordamiento dentro del tiempo de un tick, estamos en un aprieto.\n\nAdem\u00e1s, cuando hay m\u00faltiples cgroups involucrados, no hay garant\u00eda de que el tick realmente llegue a cada cgroup de manera oportuna. Estad\u00edsticamente hablando, lo har\u00e1, pero esas mismas estad\u00edsticas no descartan la posibilidad de que un cgroup no reciba un tick durante una cantidad significativa de tiempo, por improbable que sea.\n\nPor lo tanto, al igual que con el caso de yield(), fuerza una actualizaci\u00f3n al final de cada porci\u00f3n. Esto asegura que la actualizaci\u00f3n nunca est\u00e9 m\u00e1s de una sola porci\u00f3n atrasada y que todo est\u00e9 dentro de los 2 l\u00edmites de retraso seg\u00fan el comentario en entity_key()."}], "lastModified": "2026-11-11T20:10:00.273", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3567D859-58AE-4093-AF8D-4FAF8C4F6486", "versionEndExcluding": "6.12.81", "versionStartIncluding": "6.12.78"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "3453DC21-7215-4DEF-AA80-3E40542E64E4", "versionEndExcluding": "6.18.22", "versionStartIncluding": "6.18.17"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F9B925B8-9C64-4FC6-A4EF-B7840F1F1889", "versionEndExcluding": "6.19.12", "versionStartIncluding": "6.19.7"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}