CVE-2026-43402

{"id": "CVE-2026-43402", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-43402", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:17:02.801558Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "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": "4d13f4304fa43471bfea101658a11feec7b28ac0", "lessThan": "4729c7b00a347fd37d0cbc265b85f2884c3e06b6", "versionType": "git"}, {"status": "affected", "version": "4d13f4304fa43471bfea101658a11feec7b28ac0", "lessThan": "5a591d7a5e48d30100943940a30a6ab41b15c672", "versionType": "git"}, {"status": "affected", "version": "4d13f4304fa43471bfea101658a11feec7b28ac0", "lessThan": "28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f", "versionType": "git"}], "programFiles": ["include/linux/kthread.h", "kernel/exit.c", "kernel/kthread.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.14"}, {"status": "unaffected", "version": "0", "lessThan": "6.14", "versionType": "semver"}, {"status": "unaffected", "version": "6.18.19", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.9", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["include/linux/kthread.h", "kernel/exit.c", "kernel/kthread.c"], "defaultStatus": "affected"}]}], "published": "2026-05-08T15:16:51.670", "references": [{"url": "https://git.kernel.org/stable/c/28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/4729c7b00a347fd37d0cbc265b85f2884c3e06b6", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/5a591d7a5e48d30100943940a30a6ab41b15c672", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-416"}]}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nkthread: consolidate kthread exit paths to prevent use-after-free\n\nGuillaume reported crashes via corrupted RCU callback function pointers\nduring KUnit testing. The crash was traced back to the pidfs rhashtable\nconversion which replaced the 24-byte rb_node with an 8-byte rhash_head\nin struct pid, shrinking it from 160 to 144 bytes.\n\nstruct kthread (without CONFIG_BLK_CGROUP) is also 144 bytes. With\nCONFIG_SLAB_MERGE_DEFAULT and SLAB_HWCACHE_ALIGN both round up to\n192 bytes and share the same slab cache. struct pid.rcu.func and\nstruct kthread.affinity_node both sit at offset 0x78.\n\nWhen a kthread exits via make_task_dead() it bypasses kthread_exit() and\nmisses the affinity_node cleanup. free_kthread_struct() frees the memory\nwhile the node is still linked into the global kthread_affinity_list. A\nsubsequent list_del() by another kthread writes through dangling list\npointers into the freed and reused memory, corrupting the pid's\nrcu.func pointer.\n\nInstead of patching free_kthread_struct() to handle the missed cleanup,\nconsolidate all kthread exit paths. Turn kthread_exit() into a macro\nthat calls do_exit() and add kthread_do_exit() which is called from\ndo_exit() for any task with PF_KTHREAD set. This guarantees that\nkthread-specific cleanup always happens regardless of the exit path -\nmake_task_dead(), direct do_exit(), or kthread_exit().\n\nReplace __to_kthread() with a new tsk_is_kthread() accessor in the\npublic header. Export do_exit() since module code using the\nkthread_exit() macro now needs it directly."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nkthread: consolidar las rutas de salida de kthread para prevenir el uso despu\u00e9s de liberaci\u00f3n\n\nGuillaume inform\u00f3 de fallos a trav\u00e9s de punteros de funci\u00f3n de callback RCU corruptos durante las pruebas de KUnit. El fallo se rastre\u00f3 hasta la conversi\u00f3n de rhashtable de pidfs que reemplaz\u00f3 el rb_node de 24 bytes con un rhash_head de 8 bytes en la estructura pid, reduci\u00e9ndola de 160 a 144 bytes.\n\nLa estructura kthread (sin CONFIG_BLK_CGROUP) tambi\u00e9n es de 144 bytes. Con CONFIG_SLAB_MERGE_DEFAULT y SLAB_HWCACHE_ALIGN, ambos se redondean a 192 bytes y comparten la misma cach\u00e9 de slab. struct pid.rcu.func y struct kthread.affinity_node ambos se encuentran en el desplazamiento 0x78.\n\nCuando un kthread sale a trav\u00e9s de make_task_dead(), omite kthread_exit() y la limpieza de affinity_node. free_kthread_struct() libera la memoria mientras el nodo a\u00fan est\u00e1 vinculado a la kthread_affinity_list global. Una posterior list_del() por otro kthread escribe a trav\u00e9s de punteros de lista colgantes en la memoria liberada y reutilizada, corrompiendo el puntero rcu.func del pid.\n\nEn lugar de parchear free_kthread_struct() para manejar la limpieza omitida, consolidar todas las rutas de salida de kthread. Convertir kthread_exit() en una macro que llama a do_exit() y a\u00f1adir kthread_do_exit() que es llamada desde do_exit() para cualquier tarea con PF_KTHREAD establecido. Esto garantiza que la limpieza espec\u00edfica de kthread siempre ocurre independientemente de la ruta de salida - make_task_dead(), do_exit() directo, o kthread_exit().\n\nReemplazar __to_kthread() con un nuevo accesor tsk_is_kthread() en el encabezado p\u00fablico. Exportar do_exit() ya que el c\u00f3digo del m\u00f3dulo que usa la macro kthread_exit() ahora lo necesita directamente."}], "lastModified": "2026-11-11T20:10:00.273", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7484E98E-61F0-4DCE-9DBF-83D2F75F99EB", "versionEndExcluding": "6.18.19", "versionStartIncluding": "6.14"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9", "versionEndExcluding": "6.19.9", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}