CVE-2026-98801
En el kernel de Linux se ha resuelto la siguiente vulnerabilidad:
net: restringir SO_RESERVE_MEM a sockets TCP y limitar el valor máximo
El commit 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM") y el commit d00c8ee31729 ("net: fix possible NULL deref in sock_reserve_memory") solo comprobaban sk_has_account(sk), que es verdadero tanto para sockets TCP como UDP.
Sin embargo, SO_RESERVE_MEM y sk_unused_reserved_mem() solo son compatibles actualmente con TCP: - En sockets UDP, sk->sk_forward_alloc está protegido por sk->sk_receive_queue.lock, mientras que sock_reserve_memory() y sock_release_reserved_memory() solo adquieren lock_sock(sk).
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La recepción/liberación concurrente de paquetes UDP y setsockopt(SO_RESERVE_MEM) corrompen sk_forward_alloc y la contabilidad de memcg. - udp_rmem_release() recupera el exceso de sk_forward_alloc sin tener en cuenta sk_unused_reserved_mem(sk).
Restringir sock_reserve_memory() a sockets TCP (sk_is_tcp(sk)) por ahora. El soporte de SO_RESERVE_MEM para UDP (adquiriendo sk_receive_queue.lock y respetando sk_unused_reserved_mem() en udp_rmem_release()) podrá implementarse en una serie futura de net-next si fuera necesario.
Además, rechazar con -EINVAL los valores val > SZ_1G en sk_setsockopt(SO_RESERVE_MEM). Sin un límite superior, los valores cercanos a INT_MAX provocan que sk_mem_pages(delta) y (pages << PAGE_SHIFT) desborden el entero con signo de 32 bits, corrompiendo sk->sk_forward_alloc y sk->sk_reserved_mem. Usar un límite alineado a página (SZ_1G) garantiza que el valor de sk->sk_reserved_mem redondeado a página que devuelve getsockopt(SO_RESERVE_MEM) siempre pueda pasarse de nuevo a setsockopt(SO_RESERVE_MEM).
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
- 0.17 %
- Percentil entre todas las CVEs puntuadas
- 6
- 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
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JSON original (NVD)
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{
"id": "CVE-2026-98801",
"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": "2bb2f5fb21b0486ff69b7b4a1fe03a760527d133",
"lessThan": "492e04f9a00f3cc88a1f6899417b10f3019a624e",
"versionType": "git"
},
{
"status": "affected",
"version": "2bb2f5fb21b0486ff69b7b4a1fe03a760527d133",
"lessThan": "5069ce898148bd799395c5a464e006cbb840f188",
"versionType": "git"
},
{
"status": "affected",
"version": "2bb2f5fb21b0486ff69b7b4a1fe03a760527d133",
"lessThan": "a467b05b201b5c26be52ed3081992fa9c0387648",
"versionType": "git"
},
{
"status": "affected",
"version": "2bb2f5fb21b0486ff69b7b4a1fe03a760527d133",
"lessThan": "37e02c42a00be692c06343e11779aadc45f45971",
"versionType": "git"
}
],
"programFiles": [
"net/core/sock.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/core/sock.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:34.137",
"references": [
{
"url": "https://git.kernel.org/stable/c/37e02c42a00be692c06343e11779aadc45f45971",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/492e04f9a00f3cc88a1f6899417b10f3019a624e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5069ce898148bd799395c5a464e006cbb840f188",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a467b05b201b5c26be52ed3081992fa9c0387648",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: restrict SO_RESERVE_MEM to TCP sockets and cap max value\n\nCommit 2bb2f5fb21b0 (\"net: add new socket option SO_RESERVE_MEM\") and\ncommit d00c8ee31729 (\"net: fix possible NULL deref in sock_reserve_memory\")\nonly checked sk_has_account(sk), which is true for both TCP and UDP\nsockets.\n\nHowever, SO_RESERVE_MEM and sk_unused_reserved_mem() are currently only\nsupported by TCP:\n- On UDP sockets, sk->sk_forward_alloc is protected by\n sk->sk_receive_queue.lock, whereas sock_reserve_memory() and\n sock_release_reserved_memory() only acquire lock_sock(sk). Concurrent\n UDP packet reception/release and setsockopt(SO_RESERVE_MEM) corrupt\n sk_forward_alloc and memcg accounting.\n- udp_rmem_release() reclaims excess sk_forward_alloc without\n accounting for sk_unused_reserved_mem(sk).\n\nRestrict sock_reserve_memory() to TCP sockets (sk_is_tcp(sk)) for now.\nSupporting SO_RESERVE_MEM for UDP (acquiring sk_receive_queue.lock and\nhonoring sk_unused_reserved_mem() in udp_rmem_release()) can be done in\na future net-next series if needed.\n\nIn addition, reject val > SZ_1G with -EINVAL in\nsk_setsockopt(SO_RESERVE_MEM). Without an upper bound, values near\nINT_MAX cause sk_mem_pages(delta) and (pages << PAGE_SHIFT) to overflow\n32-bit signed int, corrupting sk->sk_forward_alloc and\nsk->sk_reserved_mem. Using a page-aligned cap (SZ_1G) ensures that the\npage-rounded sk->sk_reserved_mem reported by getsockopt(SO_RESERVE_MEM)\ncan always be passed back to setsockopt(SO_RESERVE_MEM)."
}
],
"lastModified": "2026-10-19T10:19:44.163",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}