CVE-2024-36943

{"id": "CVE-2024-36943", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.0}]}, "published": "2024-05-30T16:15:17.307", "references": [{"url": "https://git.kernel.org/stable/c/74b3d66f91d9f539f99faad74d796fa9a389a015", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c70dce4982ce1718bf978a35f8e26160b82081f4", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/74b3d66f91d9f539f99faad74d796fa9a389a015", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}, {"url": "https://git.kernel.org/stable/c/c70dce4982ce1718bf978a35f8e26160b82081f4", "tags": ["Patch"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan\n\nmake_uffd_wp_pte() was previously doing:\n\n pte = ptep_get(ptep);\n ptep_modify_prot_start(ptep);\n pte = pte_mkuffd_wp(pte);\n ptep_modify_prot_commit(ptep, pte);\n\nBut if another thread accessed or dirtied the pte between the first 2\ncalls, this could lead to loss of that information. Since\nptep_modify_prot_start() gets and clears atomically, the following is the\ncorrect pattern and prevents any possible race. Any access after the\nfirst call would see an invalid pte and cause a fault:\n\n pte = ptep_modify_prot_start(ptep);\n pte = pte_mkuffd_wp(pte);\n ptep_modify_prot_commit(ptep, pte);"}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: fs/proc/task_mmu: corrige la p\u00e9rdida de bits j\u00f3venes/sucios durante el escaneo del mapa de p\u00e1ginas que make_uffd_wp_pte() estaba haciendo anteriormente: pte = ptep_get(ptep); ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep,pte); Pero si otro hilo accedi\u00f3 o ensuci\u00f3 el pte entre las 2 primeras llamadas, esto podr\u00eda provocar la p\u00e9rdida de esa informaci\u00f3n. Dado que ptep_modify_prot_start() obtiene y borra at\u00f3micamente, el siguiente es el patr\u00f3n correcto y evita cualquier posible ejecuci\u00f3n. Cualquier acceso despu\u00e9s de la primera llamada ver\u00eda un pte no v\u00e1lido y provocar\u00eda una falla: pte = ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep,pte);"}], "lastModified": "2025-10-01T14:01:41.420", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6A6B920C-8D8F-4130-86B4-AD334F4CF2E3", "versionEndExcluding": "6.8.10", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "22BEDD49-2C6D-402D-9DBF-6646F6ECD10B"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DF73CB2A-DFFD-46FB-9BFE-AA394F27EA37"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "52048DDA-FC5A-4363-95A0-A6357B4D7F8C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A06B2CCF-3F43-4FA9-8773-C83C3F5764B2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F850DCEC-E08B-4317-A33B-D2DCF39F601B"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "91326417-E981-482E-A5A3-28BC1327521B"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.9:rc7:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DAECDCD8-F556-4606-8D7B-5C6D47A501F2"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}