CVE-2026-98798
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:
net: bcmgenet: corregir desreferencia NULL en set_coalesce antes de la primera apertura
Los atributos priv e index del anillo Rx solo se configuran en bcmgenet_init_rx_ring(), que se ejecuta al abrir. Al configurar los parámetros de coalescencia Rx en una interfaz que nunca se ha abierto, p. ej. "ethtool -C eth0 rx-usecs 50", se desreferencia un ring->priv NULL. El fallo se produce con RTNL bloqueado, por lo que la red queda bloqueada hasta un reinicio:
Se configuran priv e index en el sondeo. Escribir en los registros mientras la interfaz está apagada es inofensivo porque la apertura reinicia la MAC y bcmgenet_init_rx_coalesce() reaplica los valores almacenados.
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Se observó en una Raspberry Pi CM4, pero debería aplicarse a todos los demás dispositivos genet.
Detalles técnicos trazas, registros y código del informe original
Unable to handle kernel paging request at virtual address 0000000000002788 pc : bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 lr : bcmgenet_set_coalesce+0xe8/0x180 Call trace: bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 (P) __ethnl_set_coalesce.isra.0+0x490/0x570 ethnl_set_coalesce+0x48/0xc0 ethnl_default_set_doit+0xf4/0x230 genl_family_rcv_msg_doit+0xe8/0x160 genl_rcv_msg+0x220/0x2a0 netlink_rcv_skb+0x68/0x140 genl_rcv+0x40/0x60 netlink_unicast+0x338/0x3c0 netlink_sendmsg+0x19c/0x3f8 __sock_sendmsg+0x64/0xc0 __sys_sendto+0x124/0x198 __arm64_sys_sendto+0x30/0x48
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
Mostrar las 4 referencias
JSON original (NVD)
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{
"id": "CVE-2026-98798",
"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": "9f4ca05827a27ec73bf63a42732f1978b8a779af",
"lessThan": "0d867b91598b6ed2f75998c34f4e2869631da31e",
"versionType": "git"
},
{
"status": "affected",
"version": "9f4ca05827a27ec73bf63a42732f1978b8a779af",
"lessThan": "2294b62eaec6fd3c76a261d287f66641eeafd5f0",
"versionType": "git"
},
{
"status": "affected",
"version": "9f4ca05827a27ec73bf63a42732f1978b8a779af",
"lessThan": "d870102b5425390cab42eebbf3d19ec6a43c6734",
"versionType": "git"
},
{
"status": "affected",
"version": "9f4ca05827a27ec73bf63a42732f1978b8a779af",
"lessThan": "19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/broadcom/genet/bcmgenet.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.17"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.17",
"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": [
"drivers/net/ethernet/broadcom/genet/bcmgenet.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:33.807",
"references": [
{
"url": "https://git.kernel.org/stable/c/0d867b91598b6ed2f75998c34f4e2869631da31e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/19419faf58dfe5bcc8a9e60e622976c5f8e3ddc1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2294b62eaec6fd3c76a261d287f66641eeafd5f0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d870102b5425390cab42eebbf3d19ec6a43c6734",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: bcmgenet: fix NULL dereference in set_coalesce before first open\n\nThe Rx ring priv and index are only set in bcmgenet_init_rx_ring(),\nwhich runs at open. Setting the Rx coalescing parameters on an interface\nthat was never opened, e.g. \"ethtool -C eth0 rx-usecs 50\", dereferences\na NULL ring->priv. The oops happens with RTNL held, so networking\nstays stuck until a reboot:\n\n Unable to handle kernel paging request at virtual address 0000000000002788\n pc : bcmgenet_set_rx_coalesce.isra.0+0x10/0x88\n lr : bcmgenet_set_coalesce+0xe8/0x180\n Call trace:\n bcmgenet_set_rx_coalesce.isra.0+0x10/0x88 (P)\n __ethnl_set_coalesce.isra.0+0x490/0x570\n ethnl_set_coalesce+0x48/0xc0\n ethnl_default_set_doit+0xf4/0x230\n genl_family_rcv_msg_doit+0xe8/0x160\n genl_rcv_msg+0x220/0x2a0\n netlink_rcv_skb+0x68/0x140\n genl_rcv+0x40/0x60\n netlink_unicast+0x338/0x3c0\n netlink_sendmsg+0x19c/0x3f8\n __sock_sendmsg+0x64/0xc0\n __sys_sendto+0x124/0x198\n __arm64_sys_sendto+0x30/0x48\n\nSet priv and index at probe. Writing the registers while the interface\nis down is harmless because open resets the MAC and\nbcmgenet_init_rx_coalesce() reapplies the stored values.\n\nIt was observed on a Raspberry Pi CM4, but should apply to all other\ngenet devices."
}
],
"lastModified": "2026-10-19T10:19:43.830",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}