Heimdall Security Logo

CVE-2026-98276

Vulnérabilité élevée dans Linux (Linux)

CVSS 7.8 · Élevée
EPSS 0.1%
Linux•Linux•Versions : <=6.1.*, <d9f96bc2d822501f84d1caa6275a2c6b316ca2c4, <=6.12.*, <17b2a1eb97fdb2a2cbaeab3b146b26797ea9311f, 2.6.12, <3b12d3967e96f1b7b977d9fc352ae29a1b299a82, <899650bbf985b7bfd2a7b808357df9b16e6d6959, 0, <1f73253add8365d0dad0a4f421acaa8c21d20cef, <18899e2e4023369a8f7739c2255a59a9748d8d17, <2.6.12, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 6.12.112, 5.10.271, 6.6.158, <9ed55f3dbef4f4adfe65eb03b0c35c53229a8490, <=5.10.*, <=6.6.*, 6.1.189, 7.2.8, <=6.18.*, 5.15.222, <88c804847dd87dc613b771b392ccecdb94725032, <=7.2.*, <=*, <=5.15.*, 6.18.54, 7.3

Description

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. 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. 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) 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: 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/0x2a0 Only grab the socket lock when SOCK_TIMESTAMP has to be set, to keep the common case lockless.

Gravité et risque d'exploitation

CVE-2026-98276 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.14 %, ce qui la place devant 2.6 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <d9f96bc2d822501f84d1caa6275a2c6b316ca2c4, <=6.12.*, <17b2a1eb97fdb2a2cbaeab3b146b26797ea9311f, 2.6.12, <3b12d3967e96f1b7b977d9fc352ae29a1b299a82, <899650bbf985b7bfd2a7b808357df9b16e6d6959, 0, <1f73253add8365d0dad0a4f421acaa8c21d20cef, <18899e2e4023369a8f7739c2255a59a9748d8d17, <2.6.12, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 6.12.112, 5.10.271, 6.6.158, <9ed55f3dbef4f4adfe65eb03b0c35c53229a8490, <=5.10.*, <=6.6.*, 6.1.189, 7.2.8, <=6.18.*, 5.15.222, <88c804847dd87dc613b771b392ccecdb94725032, <=7.2.*, <=*, <=5.15.*, 6.18.54, 7.3) est présent sur votre parc.
  • Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
  • À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
  • Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

Rechercher une autre CVE