CVE-2026-98276
Estado: RecibidaSin puntuar—
In the Linux kernel, the following vulnerability has been resolved:
net: lock the socket in sock_gettstamp()
sk->sk_flags must only be changed while holding the socket lock, because sock_set_flag() and sock_reset_flag() use non atomic operations (__set_bit() and __clear_bit()).
sock_gettstamp() is one of the last places where a bit of sk->sk_flags is changed from a syscall without owning the socket lock, through sock_enable_timestamp(sk, SOCK_TIMESTAMP).
sk_set_memalloc() and sk_clear_memalloc() also change sk->sk_flags without the socket lock, but their callers (nbd, iscsi_tcp, nvme-tcp, sunrpc, wireguard) need a careful audit, this will be addressed in a separate patch.
Leer descripción completaMostrar menos
Jungwoo Lee and Wongi Lee reported an UDP socket use-after-free caused by this bug: a SIOCGSTAMPNS_NEW ioctl racing with bind() can cancel the SOCK_RCU_FREE bit that udp_lib_get_port() just set, because both threads perform a read-modify-write on the same word.
After the lost update, SOCK_RCU_FREE is clear while the socket is visible to lockless UDP receive lookups. sk_destruct() then frees the socket immediately instead of waiting for a RCU grace period, while the receive path still holds a reference-less pointer to it:
Only grab the socket lock when SOCK_TIMESTAMP has to be set, to keep the common case lockless.
Detalles técnicos trazas, registros y código del informe original
CPU 0 (bind) CPU 1 (SIOCGSTAMPNS_NEW)
-------------------------------- ----------------------------
read sk_flags = F read sk_flags = F
compute F | BIT(SOCK_RCU_FREE) compute F | BIT(SOCK_TIMESTAMP)
store F | BIT(SOCK_RCU_FREE)
sk_add_node_rcu(sk, ...)
store F | BIT(SOCK_TIMESTAMP)
BUG: KASAN: slab-use-after-free in ipv4_pktinfo_prepare+0x30/0x410
Read of size 8 at addr ffff888008806610 by task exploit/207
CPU: 0 UID: 1000 PID: 207 Comm: exploit Not tainted 6.12.95+ #1
ipv4_pktinfo_prepare+0x30/0x410
udp_queue_rcv_one_skb+0x51c/0x1180
udp_unicast_rcv_skb+0x109/0x350
ip_protocol_deliver_rcu+0x14b/0x310
ip_local_deliver_finish+0x29d/0x390
ip_local_deliver+0x24d/0x2a0CVSS
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: 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/17b2a1eb97fdb2a2cbaeab3b146b26797ea9311f
- https://git.kernel.org/stable/c/18899e2e4023369a8f7739c2255a59a9748d8d17
- https://git.kernel.org/stable/c/1f73253add8365d0dad0a4f421acaa8c21d20cef
- https://git.kernel.org/stable/c/3b12d3967e96f1b7b977d9fc352ae29a1b299a82
- https://git.kernel.org/stable/c/88c804847dd87dc613b771b392ccecdb94725032
- https://git.kernel.org/stable/c/899650bbf985b7bfd2a7b808357df9b16e6d6959
- https://git.kernel.org/stable/c/9ed55f3dbef4f4adfe65eb03b0c35c53229a8490
- https://git.kernel.org/stable/c/d9f96bc2d822501f84d1caa6275a2c6b316ca2c4
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-98276",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
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{
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"published": "2026-10-06T09:18:17.360",
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}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: lock the socket in sock_gettstamp()\n\nsk->sk_flags must only be changed while holding the socket lock,\nbecause sock_set_flag() and sock_reset_flag() use non atomic\noperations (__set_bit() and __clear_bit()).\n\nsock_gettstamp() is one of the last places where a bit of sk->sk_flags\nis changed from a syscall without owning the socket lock, through\nsock_enable_timestamp(sk, SOCK_TIMESTAMP).\n\nsk_set_memalloc() and sk_clear_memalloc() also change sk->sk_flags\nwithout the socket lock, but their callers (nbd, iscsi_tcp, nvme-tcp,\nsunrpc, wireguard) need a careful audit, this will be addressed in a\nseparate patch.\n\nJungwoo Lee and Wongi Lee reported an UDP socket use-after-free\ncaused by this bug: a SIOCGSTAMPNS_NEW ioctl racing with bind()\ncan cancel the SOCK_RCU_FREE bit that udp_lib_get_port() just set,\nbecause both threads perform a read-modify-write on the same word.\n\n CPU 0 (bind) CPU 1 (SIOCGSTAMPNS_NEW)\n -------------------------------- ----------------------------\n read sk_flags = F read sk_flags = F\n compute F | BIT(SOCK_RCU_FREE) compute F | BIT(SOCK_TIMESTAMP)\n store F | BIT(SOCK_RCU_FREE)\n sk_add_node_rcu(sk, ...)\n store F | BIT(SOCK_TIMESTAMP)\n\nAfter the lost update, SOCK_RCU_FREE is clear while the socket is\nvisible to lockless UDP receive lookups. sk_destruct() then frees\nthe socket immediately instead of waiting for a RCU grace period,\nwhile the receive path still holds a reference-less pointer to it:\n\n BUG: KASAN: slab-use-after-free in ipv4_pktinfo_prepare+0x30/0x410\n Read of size 8 at addr ffff888008806610 by task exploit/207\n CPU: 0 UID: 1000 PID: 207 Comm: exploit Not tainted 6.12.95+ #1\n ipv4_pktinfo_prepare+0x30/0x410\n udp_queue_rcv_one_skb+0x51c/0x1180\n udp_unicast_rcv_skb+0x109/0x350\n ip_protocol_deliver_rcu+0x14b/0x310\n ip_local_deliver_finish+0x29d/0x390\n ip_local_deliver+0x24d/0x2a0\n\nOnly grab the socket lock when SOCK_TIMESTAMP has to be set,\nto keep the common case lockless."
}
],
"lastModified": "2026-10-06T09:18:17.360",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}