CVE-2026-98622
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:
net/sched: act_ct: no emitir WARN ante un fallo benigno de flow_offload_alloc()
flow_offload_alloc() devuelve NULL cuando la entrada de conntrack se está eliminando (por ejemplo, si coincide con un vaciado de conntrack) o cuando falla la asignación GFP_ATOMIC; ambos casos son esperables bajo carga y ninguno es un fallo del kernel. Esta ruta se ejecuta desde softirq en cada paquete confirmado, por lo que, con panic_on_warn=1, un usuario sin privilegios puede provocar un pánico del sistema simplemente haciendo coincidir un vaciado de conntrack con un clasificador `tc ... action ct commit`.
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Reproducido con un repro personalizado bajo QEMU: un conjunto pequeño y fijo de flujos UDP a través de `tc filter ... action ct commit` en lo, enfrentado a hilos que inundan con peticiones ctnetlink CT_DELETE (vaciado) sin más contenido. Se activa WARNING: net/sched/act_ct.c:437 (tcf_ct_flow_table_add(), integrada en tcf_ct_act() en esta compilación) en unos 15 s en el kernel sin parchear; la misma configuración no presenta problemas en el kernel parcheado. La corrección en sí preserva el comportamiento: ambas ramas ya ejecutaban `goto err_alloc` antes y después, solo se elimina el WARN.
Traducción automática del texto original de NVD (en inglés).
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
- 0.18 %
- Percentil entre todas las CVEs puntuadas
- 7
- Fecha de la puntuación
- 20/10/2026
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
Mostrar las 8 referencias
- https://git.kernel.org/stable/c/00734f3684fcec42c319bedfe68a5d357c720b53
- https://git.kernel.org/stable/c/424ba52c0058deeb940d02cba52eb0aeb288db33
- https://git.kernel.org/stable/c/47abe7a5c4eb53269aca3506446f851572a059a3
- https://git.kernel.org/stable/c/650787233c2fd6e515a7c5f371019a9fa080ccd2
- https://git.kernel.org/stable/c/af475f599270e59313552e6c6f3af8507da672b8
- https://git.kernel.org/stable/c/d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a
- https://git.kernel.org/stable/c/d805560ad69cb266d669341ca01e26bffb0d2c67
- https://git.kernel.org/stable/c/e8fcf3f08834e939b797311742ee72b1e2a08096
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98622",
"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",
"versions": [
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "e8fcf3f08834e939b797311742ee72b1e2a08096",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "af475f599270e59313552e6c6f3af8507da672b8",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "424ba52c0058deeb940d02cba52eb0aeb288db33",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "d805560ad69cb266d669341ca01e26bffb0d2c67",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "00734f3684fcec42c319bedfe68a5d357c720b53",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "650787233c2fd6e515a7c5f371019a9fa080ccd2",
"versionType": "git"
},
{
"status": "affected",
"version": "64ff70b80fd403110b67dd9f7184a604fdb0da43",
"lessThan": "47abe7a5c4eb53269aca3506446f851572a059a3",
"versionType": "git"
}
],
"programFiles": [
"net/sched/act_ct.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.271",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.222",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.189",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.158",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/act_ct.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:15.117",
"references": [
{
"url": "https://git.kernel.org/stable/c/00734f3684fcec42c319bedfe68a5d357c720b53",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/424ba52c0058deeb940d02cba52eb0aeb288db33",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/47abe7a5c4eb53269aca3506446f851572a059a3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/650787233c2fd6e515a7c5f371019a9fa080ccd2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/af475f599270e59313552e6c6f3af8507da672b8",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d805560ad69cb266d669341ca01e26bffb0d2c67",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e8fcf3f08834e939b797311742ee72b1e2a08096",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: don't WARN on benign flow_offload_alloc() failure\n\nflow_offload_alloc() returns NULL when the conntrack entry is dying\n(e.g. raced with a conntrack flush) or when the GFP_ATOMIC allocation\nfails; both are expected under load and neither is a kernel bug. This\npath runs from softirq on every committed packet, so with\npanic_on_warn=1 an unprivileged user can panic the box just by racing\na conntrack flush against a `tc ... action ct commit` classifier.\n\nReproduced with a custom repro under QEMU: a small, fixed set of UDP\nflows through `tc filter ... action ct commit` on lo, raced against\nthreads flooding bare ctnetlink CT_DELETE (flush) requests. Hits\nWARNING: net/sched/act_ct.c:437 (tcf_ct_flow_table_add(), inlined\ninto tcf_ct_act() in this build) within ~15s on the unpatched kernel;\nsame setup is clean on the patched kernel. The fix itself is\nbehavior-preserving: both branches already did `goto err_alloc`\nbefore and after, only the WARN is removed."
}
],
"lastModified": "2026-10-19T10:19:26.330",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}