CVE-2022-49081

{"id": "CVE-2022-49081", "cveTags": [], "metrics": {"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}]}, "published": "2025-02-26T07:00:45.450", "references": [{"url": "https://git.kernel.org/stable/c/66f133ceab7456c789f70a242991ed1b27ba1c3d", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/7dd5b3b97716a611fcf67d92fd2370fcb8d50372", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/85550b0f5fa5dd3c30469ea702c44444ef242c83", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/c21d040de6225414547d9bd31cd200f290991c85", "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\nhighmem: fix checks in __kmap_local_sched_{in,out}\n\nWhen CONFIG_DEBUG_KMAP_LOCAL is enabled __kmap_local_sched_{in,out} check\nthat even slots in the tsk->kmap_ctrl.pteval are unmapped. The slots are\ninitialized with 0 value, but the check is done with pte_none. 0 pte\nhowever does not necessarily mean that pte_none will return true. e.g.\non xtensa it returns false, resulting in the following runtime warnings:\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108\n CPU: 0 PID: 101 Comm: touch Not tainted 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n dump_stack+0xc/0x40\n __warn+0x8f/0x174\n warn_slowpath_fmt+0x48/0xac\n __kmap_local_sched_out+0x51/0x108\n __schedule+0x71a/0x9c4\n preempt_schedule_irq+0xa0/0xe0\n common_exception_return+0x5c/0x93\n do_wp_page+0x30e/0x330\n handle_mm_fault+0xa70/0xc3c\n do_page_fault+0x1d8/0x3c4\n common_exception+0x7f/0x7f\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0\n CPU: 0 PID: 101 Comm: touch Tainted: G W 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n dump_stack+0xc/0x40\n __warn+0x8f/0x174\n warn_slowpath_fmt+0x48/0xac\n __kmap_local_sched_in+0x50/0xe0\n finish_task_switch$isra$0+0x1ce/0x2f8\n __schedule+0x86e/0x9c4\n preempt_schedule_irq+0xa0/0xe0\n common_exception_return+0x5c/0x93\n do_wp_page+0x30e/0x330\n handle_mm_fault+0xa70/0xc3c\n do_page_fault+0x1d8/0x3c4\n common_exception+0x7f/0x7f\n\nFix it by replacing !pte_none(pteval) with pte_val(pteval) != 0."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: highmem: se corrigen las comprobaciones en __kmap_local_sched_{in,out}. Cuando CONFIG_DEBUG_KMAP_LOCAL est\u00e1 habilitado, __kmap_local_sched_{in,out} comprueba que ni siquiera las ranuras en tsk->kmap_ctrl.pteval est\u00e9n asignadas. Las ranuras se inicializan con el valor 0, pero la comprobaci\u00f3n se realiza con pte_none. Sin embargo, 0 pte no significa necesariamente que pte_none devuelva verdadero. p. ej. en xtensa devuelve falso, lo que genera las siguientes advertencias de tiempo de ejecuci\u00f3n: ADVERTENCIA: CPU: 0 PID: 101 en mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108 CPU: 0 PID: 101 Comm: touch No contaminado 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13 Seguimiento de llamadas: dump_stack+0xc/0x40 __warn+0x8f/0x174 warn_slowpath_fmt+0x48/0xac __kmap_local_sched_out+0x51/0x108 __schedule+0x71a/0x9c4 preempt_schedule_irq+0xa0/0xe0 common_exception_return+0x5c/0x93 do_wp_page+0x30e/0x330 handle_mm_fault+0xa70/0xc3c do_page_fault+0x1d8/0x3c4 common_exception+0x7f/0x7f ADVERTENCIA: CPU: 0 PID: 101 en mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0 CPU: 0 PID: 101 Comm: toque Contaminado: GW 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13 Seguimiento de llamadas: dump_stack+0xc/0x40 __warn+0x8f/0x174 warn_slowpath_fmt+0x48/0xac __kmap_local_sched_in+0x50/0xe0 Soluci\u00f3nelo reemplazando !pte_none(pteval) con pte_val(pteval) != 0."}], "lastModified": "2025-10-14T20:24:06.127", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D25878D3-7761-4E9F-8919-E92CD53896E0", "versionEndExcluding": "5.15.34", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "ABBBA66E-0244-4621-966B-9790AF1EEB00", "versionEndExcluding": "5.16.20", "versionStartIncluding": "5.16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AE420AC7-1E59-4398-B84F-71F4B4337762", "versionEndExcluding": "5.17.3", "versionStartIncluding": "5.17"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:5.18:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6AD94161-84BB-42E6-9882-4FC0C42E9FC1"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}