CVE-2026-98368
Estado: RecibidaSin puntuar—
In the Linux kernel, the following vulnerability has been resolved:
esp: downgrade zerocopy managed frags before mutating skb frags
On the out-of-place output path (esp->inplace == false) ESP rewrites the skb frag array: esp_output_head() appends a trailer frag and esp_output_tail() replaces the frags with a destination page, both referenced with get_page().
When the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the payload frags are owned by the ubuf and must not be referenced or unreferenced individually, but ESP mutates the frag array without ever downgrading the skb. This breaks the managed-frag invariant two ways:
Leer descripción completaMostrar menos
Fix this the way every other frag-mutating site does (__ip_append_data(), __ip6_append_data(), tcp_sendmsg_locked()) and call skb_zcopy_downgrade_managed() before ESP touches the frag array: it takes a real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS, so the per-frag unref in esp_ssg_unref() and the frag release in skb_release_data() are both balanced and no mixed-ownership frag array is left behind.
Detalles técnicos trazas, registros y código del informe original
- esp_ssg_unref() walks the source scatterlist and drops a page
reference for every frag, including the ubuf-owned payload frags,
pushing their refcount below the GUP pin bias while the pages are
still pinned, i.e. a use-after-free of the zerocopy pages;
- esp_output_tail() installs its destination page as frag 0 with
get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so
skb_release_data() takes the skip_unref branch and never drops that
reference, leaking the x->xfrag page at packet rate.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: 6
- 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
- https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6
- https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3
- https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134
- https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d
- https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844
- https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98368",
"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": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "2359264f377cdbdef2d95868cc8fb572949e48d3",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "69a768c12398cada8528080332c822623fa7064d",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "6508304ac2c8cdafca2f4ab915df8c707893e134",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "6cab554f2c0f28773f712ed3a5479103f42ce844",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "0d0845ee61c5df47cc68bc446501f48f71e8dcc6",
"versionType": "git"
},
{
"status": "affected",
"version": "753f1ca4e1e50248a1b760c9774d6d6b354562cc",
"lessThan": "f89416eb3db151170a6f3c6dfc5239d26cdce4d2",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.0",
"versionType": "semver"
},
{
"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": "6.18.54",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.8",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc4",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/esp4.c",
"net/ipv6/esp6.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-06T09:18:31.130",
"references": [
{
"url": "https://git.kernel.org/stable/c/0d0845ee61c5df47cc68bc446501f48f71e8dcc6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2359264f377cdbdef2d95868cc8fb572949e48d3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6508304ac2c8cdafca2f4ab915df8c707893e134",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/69a768c12398cada8528080332c822623fa7064d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6cab554f2c0f28773f712ed3a5479103f42ce844",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f89416eb3db151170a6f3c6dfc5239d26cdce4d2",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nesp: downgrade zerocopy managed frags before mutating skb frags\n\nOn the out-of-place output path (esp->inplace == false) ESP rewrites the\nskb frag array: esp_output_head() appends a trailer frag and\nesp_output_tail() replaces the frags with a destination page, both\nreferenced with get_page().\n\nWhen the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the\npayload frags are owned by the ubuf and must not be referenced or\nunreferenced individually, but ESP mutates the frag array without ever\ndowngrading the skb. This breaks the managed-frag invariant two ways:\n\n - esp_ssg_unref() walks the source scatterlist and drops a page\n reference for every frag, including the ubuf-owned payload frags,\n pushing their refcount below the GUP pin bias while the pages are\n still pinned, i.e. a use-after-free of the zerocopy pages;\n\n - esp_output_tail() installs its destination page as frag 0 with\n get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so\n skb_release_data() takes the skip_unref branch and never drops that\n reference, leaking the x->xfrag page at packet rate.\n\nFix this the way every other frag-mutating site does (__ip_append_data(),\n__ip6_append_data(), tcp_sendmsg_locked()) and call\nskb_zcopy_downgrade_managed() before ESP touches the frag array: it takes\na real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS,\nso the per-frag unref in esp_ssg_unref() and the frag release in\nskb_release_data() are both balanced and no mixed-ownership frag array is\nleft behind."
}
],
"lastModified": "2026-10-06T09:18:31.130",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}