CVE-2026-74664
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reallocate update replies for mismatched IDs ovs_flow_cmd_new() preallocates the optional reply skb before it takes ovs_mutex and before it knows which existing flow will be updated. That is normally fine because the skb is sized from the request flow identifier. That identifier also becomes the inserted flow's identifier. For updates, however, a request with a UFID may miss the UFID lookup and then fall back to the flow key lookup. That lookup can legitimately find an existing key-identified flow. UFIDs are optional and the flow key is the primary identifier. For echoed replies, ovs_flow_cmd_fill_info() writes the matched flow's identifier, not the request identifier used for the preallocation. A short request UFID can therefore leave too little room for the key identifier. The fill can then fail with -EMSGSIZE and hit the BUG_ON(error < 0) in the update path. Once the update target has been resolved, reallocate the reply skb if the matched flow needs a larger reply than the request identifier allowed. Do this before replacing the actions so the request can still fail cleanly if the rare extra allocation fails.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-22 16:16:40.220000
Last modified
2026-11-06 17:19:53.153000
View original CVE JSON
{
"id": "CVE-2026-74664",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-22T16:16:40.220",
"lastModified": "2026-11-06T17:19:53.153",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: reallocate update replies for mismatched IDs\n\novs_flow_cmd_new() preallocates the optional reply skb before it takes\novs_mutex and before it knows which existing flow will be updated.\n\nThat is normally fine because the skb is sized from the request flow\nidentifier. That identifier also becomes the inserted flow's identifier.\nFor updates, however, a request with a UFID may miss the UFID lookup and\nthen fall back to the flow key lookup. That lookup can legitimately find\nan existing key-identified flow. UFIDs are optional and the flow key is\nthe primary identifier.\n\nFor echoed replies, ovs_flow_cmd_fill_info() writes the matched flow's\nidentifier, not the request identifier used for the preallocation. A short\nrequest UFID can therefore leave too little room for the key identifier.\nThe fill can then fail with -EMSGSIZE and hit the BUG_ON(error < 0) in the\nupdate path.\n\nOnce the update target has been resolved, reallocate the reply skb if the\nmatched flow needs a larger reply than the request identifier allowed. Do\nthis before replacing the actions so the request can still fail cleanly if\nthe rare extra allocation fails."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:\n\nnet: openvswitch: reasignar respuestas de actualización para IDs no coincidentes\n\novs_flow_cmd_new() preasigna el skb de respuesta opcional antes de tomar ovs_mutex y antes de saber qué flujo existente se actualizará.\n\nEsto normalmente está bien porque el skb se dimensiona a partir del identificador de flujo de la solicitud. Ese identificador también se convierte en el identificador del flujo insertado. Para las actualizaciones, sin embargo, una solicitud con un UFID puede fallar en la búsqueda de UFID y luego recurrir a la búsqueda de clave de flujo. Esa búsqueda puede encontrar legítimamente un flujo existente identificado por clave. Los UFID son opcionales y la clave de flujo es el identificador principal.\n\nPara las respuestas con eco, ovs_flow_cmd_fill_info() escribe el identificador del flujo coincidente, no el identificador de la solicitud utilizado para la preasignación. Un UFID de solicitud corto puede, por lo tanto, dejar muy poco espacio para el identificador de clave. El llenado puede entonces fallar con -EMSGSIZE y activar el BUG_ON(error < 0) en la ruta de actualización.\n\nUna vez que se ha resuelto el objetivo de actualización, reasigne el skb de respuesta si el flujo coincidente necesita una respuesta más grande de lo que permitía el identificador de la solicitud. Haga esto antes de reemplazar las acciones para que la solicitud aún pueda fallar limpiamente si la rara asignación adicional falla."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/openvswitch/datapath.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"status": "affected"
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{
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"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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},
{
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"lessThanOrEqual": "5.15.*",
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},
{
"version": "6.1.183",
"lessThanOrEqual": "6.1.*",
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"status": "unaffected"
},
{
"version": "6.6.152",
"lessThanOrEqual": "6.6.*",
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"status": "unaffected"
},
{
"version": "6.12.104",
"lessThanOrEqual": "6.12.*",
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"status": "unaffected"
},
{
"version": "6.18.45",
"lessThanOrEqual": "6.18.*",
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},
{
"version": "7.1.9",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T17:00:43.008872Z",
"id": "CVE-2026-74664",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
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