CVE-2022-49955

{"id": "CVE-2022-49955", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "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": "2025-06-18T11:15:22.630", "references": [{"url": "https://git.kernel.org/stable/c/8b08d4f97233d8e58fff2fd9d5f86397a49733c5", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/91926d8b7e71aaf5f84f0cf208fc5a8b7a761050", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/rtas: Fix RTAS MSR[HV] handling for Cell\n\nThe semi-recent changes to MSR handling when entering RTAS (firmware)\ncause crashes on IBM Cell machines. An example trace:\n\n kernel tried to execute user page (2fff01a8) - exploit attempt? (uid: 0)\n BUG: Unable to handle kernel instruction fetch\n Faulting instruction address: 0x2fff01a8\n Oops: Kernel access of bad area, sig: 11 [#1]\n BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=4 NUMA Cell\n Modules linked in:\n CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.0.0-rc2-00433-gede0a8d3307a #207\n NIP: 000000002fff01a8 LR: 0000000000032608 CTR: 0000000000000000\n REGS: c0000000015236b0 TRAP: 0400 Tainted: G W (6.0.0-rc2-00433-gede0a8d3307a)\n MSR: 0000000008001002 <ME,RI> CR: 00000000 XER: 20000000\n ...\n NIP 0x2fff01a8\n LR 0x32608\n Call Trace:\n 0xc00000000143c5f8 (unreliable)\n .rtas_call+0x224/0x320\n .rtas_get_boot_time+0x70/0x150\n .read_persistent_clock64+0x114/0x140\n .read_persistent_wall_and_boot_offset+0x24/0x80\n .timekeeping_init+0x40/0x29c\n .start_kernel+0x674/0x8f0\n start_here_common+0x1c/0x50\n\nUnlike PAPR platforms where RTAS is only used in guests, on the IBM Cell\nmachines Linux runs with MSR[HV] set but also uses RTAS, provided by\nSLOF.\n\nFix it by copying the MSR[HV] bit from the MSR value we've just read\nusing mfmsr into the value used for RTAS.\n\nIt seems like we could also fix it using an #ifdef CELL to set MSR[HV],\nbut that doesn't work because it's possible to build a single kernel\nimage that runs on both Cell native and pseries."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: powerpc/rtas: Correcci\u00f3n del manejo de MSR[HV] de RTAS para Cell. Los cambios recientes en el manejo de MSR al ingresar RTAS (firmware) provocan bloqueos en las m\u00e1quinas IBM Cell. Ejemplo de rastreo: el kernel intent\u00f3 ejecutar la p\u00e1gina de usuario (2fff01a8): \u00bfintento de explotaci\u00f3n? (uid: 0) ERROR: No se puede controlar la obtenci\u00f3n de instrucciones del n\u00facleo Direcci\u00f3n de instrucci\u00f3n err\u00f3nea: 0x2fff01a8 Oops: Acceso del n\u00facleo al \u00e1rea defectuosa, firma: 11 [#1] BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=4 M\u00f3dulos de celda NUMA vinculados: CPU: 0 PID: 0 Comm: swapper/0 Contaminado: GW 6.0.0-rc2-00433-gede0a8d3307a #207 NIP: 000000002fff01a8 LR: 0000000000032608 CTR: 000000000000000 REGS: c0000000015236b0 TRAP: 0400 Contaminado: GW (6.0.0-rc2-00433-gede0a8d3307a) MSR: 0000000008001002 CR: 00000000 XER: 20000000 ... NIP 0x2fff01a8 LR 0x32608 Rastreo de llamadas: 0xc00000000143c5f8 (no confiable) .rtas_call+0x224/0x320 .rtas_get_boot_time+0x70/0x150 .read_persistent_clock64+0x114/0x140 .read_persistent_wall_and_boot_offset+0x24/0x80 .timekeeping_init+0x40/0x29c A diferencia de las plataformas PAPR, donde RTAS solo se usa en hu\u00e9spedes, en las m\u00e1quinas IBM Cell, Linux se ejecuta con MSR[HV] activado, pero tambi\u00e9n usa RTAS, proporcionado por SLOF. Para solucionarlo, copie el bit MSR[HV] del valor MSR que acabamos de leer con mfmsr al valor usado para RTAS. Parece que tambi\u00e9n podr\u00edamos solucionarlo usando un #ifdef CELL para activar MSR[HV], pero esto no funciona, ya que es posible crear una \u00fanica imagen de kernel que funcione tanto en Cell nativo como en pseries."}], "lastModified": "2025-11-14T18:59:35.720", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "38823576-F70F-46FB-A73D-BFB7068D387D", "versionEndExcluding": "5.16", "versionStartIncluding": "5.15.46"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "53441672-E856-4C9B-92DD-20B8133BE921", "versionEndExcluding": "5.18", "versionStartIncluding": "5.17.14"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DBEB524B-CE23-4F7F-B400-503BD7FDC334", "versionEndExcluding": "5.19.8", "versionStartIncluding": "5.18.3"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E8BD11A3-8643-49B6-BADE-5029A0117325"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5F0AD220-F6A9-4012-8636-155F1B841FAD"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A46498B3-78E1-4623-AAE1-94D29A42BE4E"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}