CVE-2026-43271

{"id": "CVE-2026-43271", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-43271", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-11-06T15:32:48.991953Z"}}], "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": "0ba959774e93911caff596de6391f085fb640ac4", "lessThan": "b65ea893290056bee380d0c8eeb47797c2bcb311", "versionType": "git"}, {"status": "affected", "version": "0ba959774e93911caff596de6391f085fb640ac4", "lessThan": "a61c1bc84c4a0f1e7c2fe55b0f43d7d94af4adf1", "versionType": "git"}, {"status": "affected", "version": "0ba959774e93911caff596de6391f085fb640ac4", "lessThan": "dec123825c1ed74d98fd5fc7571a851dea4f46ff", "versionType": "git"}, {"status": "affected", "version": "0ba959774e93911caff596de6391f085fb640ac4", "lessThan": "721599e837d3f4c0e6cc14da059612c017b6d3ec", "versionType": "git"}, {"status": "affected", "version": "0ba959774e93911caff596de6391f085fb640ac4", "lessThan": "dceb5a843910004cb118148e267036104fc3ee43", "versionType": "git"}, {"status": "affected", "version": "0ba959774e93911caff596de6391f085fb640ac4", "lessThan": "f150e753cb8dd756085f46e86f2c35ce472e0a3c", "versionType": "git"}], "programFiles": ["drivers/md/md-cluster.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "4.12"}, {"status": "unaffected", "version": "0", "lessThan": "4.12", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.191", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.128", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.75", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.16", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.6", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/md/md-cluster.c"], "defaultStatus": "affected"}]}], "published": "2026-05-06T12:16:48.313", "references": [{"url": "https://git.kernel.org/stable/c/721599e837d3f4c0e6cc14da059612c017b6d3ec", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a61c1bc84c4a0f1e7c2fe55b0f43d7d94af4adf1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b65ea893290056bee380d0c8eeb47797c2bcb311", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dceb5a843910004cb118148e267036104fc3ee43", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/dec123825c1ed74d98fd5fc7571a851dea4f46ff", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f150e753cb8dd756085f46e86f2c35ce472e0a3c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "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\nmd-cluster: fix NULL pointer dereference in process_metadata_update\n\nThe function process_metadata_update() blindly dereferences the 'thread'\npointer (acquired via rcu_dereference_protected) within the wait_event()\nmacro.\n\nWhile the code comment states \"daemon thread must exist\", there is a valid\nrace condition window during the MD array startup sequence (md_run):\n\n1. bitmap_load() is called, which invokes md_cluster_ops->join().\n2. join() starts the \"cluster_recv\" thread (recv_daemon).\n3. At this point, recv_daemon is active and processing messages.\n4. However, mddev->thread (the main MD thread) is not initialized until\n later in md_run().\n\nIf a METADATA_UPDATED message is received from a remote node during this\nspecific window, process_metadata_update() will be called while\nmddev->thread is still NULL, leading to a kernel panic.\n\nTo fix this, we must validate the 'thread' pointer. If it is NULL, we\nrelease the held lock (no_new_dev_lockres) and return early, safely\nignoring the update request as the array is not yet fully ready to\nprocess it."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:\n\nmd-cluster: correcci\u00f3n de desreferencia de puntero NULL en process_metadata_update\n\nLa funci\u00f3n process_metadata_update() desreferencia ciegamente el puntero \u2019thread\u2019 (adquirido a trav\u00e9s de rcu_dereference_protected) dentro de la macro wait_event().\n\nAunque el comentario del c\u00f3digo indica \u2019el hilo demonio debe existir\u2019, existe una ventana de condici\u00f3n de carrera v\u00e1lida durante la secuencia de inicio del array MD (md_run):\n\n1. Se llama a bitmap_load(), lo que invoca a md_cluster_ops -> join().\n2. join() inicia el hilo \u2019cluster_recv\u2019 (recv_daemon).\n3. En este punto, recv_daemon est\u00e1 activo y procesando mensajes.\n4. Sin embargo, mddev -> thread (el hilo MD principal) no se inicializa hasta m\u00e1s tarde en md_run().\n\nSi se recibe un mensaje METADATA_UPDATED de un nodo remoto durante esta ventana espec\u00edfica, process_metadata_update() ser\u00e1 llamada mientras mddev -> thread sigue siendo NULL, lo que lleva a un p\u00e1nico del kernel.\n\nPara solucionar esto, debemos validar el puntero \u2019thread\u2019. Si es NULL, liberamos el bloqueo mantenido (no_new_dev_lockres) y retornamos anticipadamente, ignorando de forma segura la solicitud de actualizaci\u00f3n ya que el array a\u00fan no est\u00e1 completamente listo para procesarla."}], "lastModified": "2026-11-11T23:10:00.263", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E90AEF03-C864-4508-AA5A-71B005F9732D", "versionEndExcluding": "6.6.128", "versionStartIncluding": "4.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2", "versionEndExcluding": "6.12.75", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B", "versionEndExcluding": "6.18.16", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67", "versionEndExcluding": "6.19.6", "versionStartIncluding": "6.19"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}