fkie_cve-2024-42256
Vulnerability from fkie_nvd
Published
2024-08-08 09:15
Modified
2024-09-06 13:56
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix server re-repick on subrequest retry
When a subrequest is marked for needing retry, netfs will call
cifs_prepare_write() which will make cifs repick the server for the op
before renegotiating credits; it then calls cifs_issue_write() which
invokes smb2_async_writev() - which re-repicks the server.
If a different server is then selected, this causes the increment of
server->in_flight to happen against one record and the decrement to happen
against another, leading to misaccounting.
Fix this by just removing the repick code in smb2_async_writev(). As this
is only called from netfslib-driven code, cifs_prepare_write() should
always have been called first, and so server should never be NULL and the
preparatory step is repeated in the event that we do a retry.
The problem manifests as a warning looking something like:
WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs]
...
RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs]
...
smb2_writev_callback+0x334/0x560 [cifs]
cifs_demultiplex_thread+0x77a/0x11b0 [cifs]
kthread+0x187/0x1d0
ret_from_fork+0x34/0x60
ret_from_fork_asm+0x1a/0x30
Which may be triggered by a number of different xfstests running against an
Azure server in multichannel mode. generic/249 seems the most repeatable,
but generic/215, generic/249 and generic/308 may also show it.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * |
{
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"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "CC5B6890-A2E7-41F8-AA56-E3202E9FB075",
"versionEndExcluding": "6.10.1",
"versionStartIncluding": "6.10",
"vulnerable": true
}
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"negate": false,
"operator": "OR"
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],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: Fix server re-repick on subrequest retry\n\nWhen a subrequest is marked for needing retry, netfs will call\ncifs_prepare_write() which will make cifs repick the server for the op\nbefore renegotiating credits; it then calls cifs_issue_write() which\ninvokes smb2_async_writev() - which re-repicks the server.\n\nIf a different server is then selected, this causes the increment of\nserver-\u003ein_flight to happen against one record and the decrement to happen\nagainst another, leading to misaccounting.\n\nFix this by just removing the repick code in smb2_async_writev(). As this\nis only called from netfslib-driven code, cifs_prepare_write() should\nalways have been called first, and so server should never be NULL and the\npreparatory step is repeated in the event that we do a retry.\n\nThe problem manifests as a warning looking something like:\n\n WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs]\n ...\n RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs]\n ...\n smb2_writev_callback+0x334/0x560 [cifs]\n cifs_demultiplex_thread+0x77a/0x11b0 [cifs]\n kthread+0x187/0x1d0\n ret_from_fork+0x34/0x60\n ret_from_fork_asm+0x1a/0x30\n\nWhich may be triggered by a number of different xfstests running against an\nAzure server in multichannel mode. generic/249 seems the most repeatable,\nbut generic/215, generic/249 and generic/308 may also show it."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: cifs: corrige la repetici\u00f3n del servidor en el reintento de subrequest Cuando se marca una subrequest para necesitar un reintento, netfs llamar\u00e1 a cifs_prepare_write(), lo que har\u00e1 que cifs vuelva a seleccionar el servidor para la operaci\u00f3n antes de renegociar los cr\u00e9ditos; luego llama a cifs_issue_write(), que invoca a smb2_async_writev(), que vuelve a seleccionar el servidor. Si luego se selecciona un servidor diferente, esto hace que el incremento de server-\u0026gt;in_flight ocurra en un registro y la disminuci\u00f3n en otro, lo que lleva a una contabilidad err\u00f3nea. Solucione este problema simplemente eliminando el c\u00f3digo de repetici\u00f3n en smb2_async_writev(). Como esto solo se llama desde c\u00f3digo controlado por netfslib, siempre se deber\u00eda haber llamado primero a cifs_prepare_write(), por lo que el servidor nunca deber\u00eda ser NULL y el paso preparatorio se repite en caso de que hagamos un reintento. El problema se manifiesta como una advertencia similar a: ADVERTENCIA: CPU: 4 PID: 72896 en fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Que puede ser activado por varios xfstests corriendo contra un Servidor Azure en modo multicanal. generic/249 parece el m\u00e1s repetible, pero generic/215, generic/249 y generic/308 tambi\u00e9n pueden mostrarlo."
}
],
"id": "CVE-2024-42256",
"lastModified": "2024-09-06T13:56:00.207",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2024-08-08T09:15:08.553",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/b1d0a566769b6fb3795b5289fc1daf9e0638d97a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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],
"url": "https://git.kernel.org/stable/c/de40579b903883274fe203865f29d66b168b7236"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
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"description": [
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"lang": "en",
"value": "NVD-CWE-noinfo"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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