CVE-2022-49955
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: powerpc/rtas: Fix RTAS MSR[HV] handling for Cell The semi-recent changes to MSR handling when entering RTAS (firmware) cause crashes on IBM Cell machines. An example trace: kernel tried to execute user page (2fff01a8) - exploit attempt? (uid: 0) BUG: Unable to handle kernel instruction fetch Faulting instruction address: 0x2fff01a8 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=4 NUMA Cell Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.0.0-rc2-00433-gede0a8d3307a #207 NIP: 000000002fff01a8 LR: 0000000000032608 CTR: 0000000000000000 REGS: c0000000015236b0 TRAP: 0400 Tainted: G W (6.0.0-rc2-00433-gede0a8d3307a) MSR: 0000000008001002 <ME,RI> CR: 00000000 XER: 20000000 ... NIP 0x2fff01a8 LR 0x32608 Call Trace: 0xc00000000143c5f8 (unreliable) .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 .start_kernel+0x674/0x8f0 start_here_common+0x1c/0x50 Unlike PAPR platforms where RTAS is only used in guests, on the IBM Cell machines Linux runs with MSR[HV] set but also uses RTAS, provided by SLOF. Fix it by copying the MSR[HV] bit from the MSR value we've just read using mfmsr into the value used for RTAS. It seems like we could also fix it using an #ifdef CELL to set MSR[HV], but that doesn't work because it's possible to build a single kernel image that runs on both Cell native and pseries.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-06-18 11:15:22.630000
Last modified
2026-11-05 20:17:18.723000
View original CVE JSON
{
"id": "CVE-2022-49955",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-06-18T11:15:22.630",
"lastModified": "2026-11-05T20:17:18.723",
"vulnStatus": "Analyzed",
"cveTags": [],
"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: Corrección 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 máquinas IBM Cell. Ejemplo de rastreo: el kernel intentó ejecutar la página de usuario (2fff01a8): ¿intento de explotación? (uid: 0) ERROR: No se puede controlar la obtención de instrucciones del núcleo Dirección de instrucción errónea: 0x2fff01a8 Oops: Acceso del núcleo al área defectuosa, firma: 11 [#1] BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=4 Módulos 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 huéspedes, en las máquinas IBM Cell, Linux se ejecuta con MSR[HV] activado, pero también 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 también podríamos solucionarlo usando un #ifdef CELL para activar MSR[HV], pero esto no funciona, ya que es posible crear una única imagen de kernel que funcione tanto en Cell nativo como en pseries."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"arch/powerpc/kernel/rtas_entry.S"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "b6b1c3ce06ca438eb24e0f45bf0e63ecad0369f5",
"lessThan": "8b08d4f97233d8e58fff2fd9d5f86397a49733c5",
"versionType": "git",
"status": "affected"
},
{
"version": "b6b1c3ce06ca438eb24e0f45bf0e63ecad0369f5",
"lessThan": "91926d8b7e71aaf5f84f0cf208fc5a8b7a761050",
"versionType": "git",
"status": "affected"
},
{
"version": "5ca40fcf0da0ce2b5bc44e7d8b036535955f2e3d",
"versionType": "git",
"status": "affected"
},
{
"version": "5f4367448f6817c8a0e94dc9736ed84fa8eee4a3",
"versionType": "git",
"status": "affected"
},
{
"version": "c9c41f0273826a13ac93124e66a4ff45df281ba0",
"versionType": "git",
"status": "affected"
},
{
"version": "5.15.46",
"lessThan": "5.16",
"versionType": "semver",
"status": "affected"
},
{
"version": "5.17.14",
"lessThan": "5.18",
"versionType": "semver",
"status": "affected"
},
{
"version": "5.18.3",
"lessThan": "5.19",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"arch/powerpc/kernel/rtas_entry.S"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.19",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.19",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.19.8",
"lessThanOrEqual": "5.19.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.0",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-05T19:51:57.598889Z",
"id": "CVE-2022-49955",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.15.46",
"versionEndExcluding": "5.16",
"matchCriteriaId": "38823576-F70F-46FB-A73D-BFB7068D387D"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.17.14",
"versionEndExcluding": "5.18",
"matchCriteriaId": "53441672-E856-4C9B-92DD-20B8133BE921"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.18.3",
"versionEndExcluding": "5.19.8",
"matchCriteriaId": "DBEB524B-CE23-4F7F-B400-503BD7FDC334"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:*",
"matchCriteriaId": "E8BD11A3-8643-49B6-BADE-5029A0117325"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:*",
"matchCriteriaId": "5F0AD220-F6A9-4012-8636-155F1B841FAD"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:*",
"matchCriteriaId": "A46498B3-78E1-4623-AAE1-94D29A42BE4E"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/8b08d4f97233d8e58fff2fd9d5f86397a49733c5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
},
{
"url": "https://git.kernel.org/stable/c/91926d8b7e71aaf5f84f0cf208fc5a8b7a761050",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
]
}
]
}