CVE-2026-97985
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Update last skb marker in manage_oob().
Fahad Alharbi reported that blocking recv(MSG_PEEK) could hog CPU due to OOB skb.
In the following cases, manage_oob() skips OOB skb(s) and returns NULL for the last recv(MSG_PEEK):
Then, @copied is 0 in unix_stream_read_generic() (zero-length buffer, or non-OOB skb is not yet consumed), and unix_stream_data_wait() is called.
However, it returns immediately because @last is not updated in unix_stream_read_generic(), and the thread busy-waits for a new skb.
Let's update @last in manage_oob().
Leer descripción completaMostrar menos
For MSG_PEEK, @last is updated with the skipped OOB, and for the non-peek case, @last matches the returned value (when !copied) because OOB is unlinked.
Note that manage_oob() is inlined and no stack canary is added.
Detalles técnicos trazas, registros y código del informe original
socketpair(AF_UNIX, SOCK_STREAM, 0, sk);
1) skb -> OOB skb -> NULL
send(sk[0], "ab", 2, MSG_OOB);
recv(sk[1], buf, 0, MSG_PEEK);
2) skb -> consumed OOB skb -> NULL
send(sk[0], "ab", 2, MSG_OOB);
recv(sk[1], buf, 1, MSG_OOB);
recv(sk[1], buf, 0, MSG_PEEK);
3) consumed OOB skb -> OOB skb -> NULL
send(sk[0], "a", 1, MSG_OOB);
recv(sk[1], buf, 0, MSG_OOB);
send(sk[0], "b", 1, MSG_OOB);
recv(sk[1], buf, 1, MSG_PEEK);CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.17%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-97985",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
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{
"status": "affected",
"version": "22dd70eb2c3d754862964377a75abafd3167346b",
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{
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},
{
"status": "affected",
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"lessThan": "6.9",
"versionType": "semver"
}
],
"programFiles": [
"net/unix/af_unix.c"
],
"defaultStatus": "unaffected"
},
{
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"vendor": "Linux",
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{
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{
"status": "unaffected",
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{
"status": "unaffected",
"version": "6.18.53",
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},
{
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"version": "7.2.7",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
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],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-25T11:17:26.560",
"references": [
{
"url": "https://git.kernel.org/stable/c/0630bfc773d85ac44da05b2c5a037dbbd39301ab",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/94fd4debd2e3a69cf93e766c8b328a810c228119",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Update last skb marker in manage_oob().\n\nFahad Alharbi reported that blocking recv(MSG_PEEK) could hog CPU\ndue to OOB skb.\n\nIn the following cases, manage_oob() skips OOB skb(s) and returns\nNULL for the last recv(MSG_PEEK):\n\n socketpair(AF_UNIX, SOCK_STREAM, 0, sk);\n\n 1) skb -> OOB skb -> NULL\n send(sk[0], \"ab\", 2, MSG_OOB);\n recv(sk[1], buf, 0, MSG_PEEK);\n\n 2) skb -> consumed OOB skb -> NULL\n send(sk[0], \"ab\", 2, MSG_OOB);\n recv(sk[1], buf, 1, MSG_OOB);\n recv(sk[1], buf, 0, MSG_PEEK);\n\n 3) consumed OOB skb -> OOB skb -> NULL\n send(sk[0], \"a\", 1, MSG_OOB);\n recv(sk[1], buf, 0, MSG_OOB);\n send(sk[0], \"b\", 1, MSG_OOB);\n recv(sk[1], buf, 1, MSG_PEEK);\n\nThen, @copied is 0 in unix_stream_read_generic() (zero-length buffer,\nor non-OOB skb is not yet consumed), and unix_stream_data_wait() is\ncalled.\n\nHowever, it returns immediately because @last is not updated in\nunix_stream_read_generic(), and the thread busy-waits for a new skb.\n\nLet's update @last in manage_oob().\n\nFor MSG_PEEK, @last is updated with the skipped OOB, and for the\nnon-peek case, @last matches the returned value (when !copied)\nbecause OOB is unlinked.\n\nNote that manage_oob() is inlined and no stack canary is added."
}
],
"lastModified": "2026-09-25T11:17:26.560",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}