CVE-2026-90078

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, <d896843d8d925f0adbba319020595cfb1a7bcd57, <=6.12.*, 5.15.221, 0, 6.1.188, 6.18.52, <81d0d1e64f30d9989c829c0953cd6e6c68d9c5fb, <62126464f3a6159c0a3dd89e196ba65bfeb0afc6, <=6.6.*, <0675cff3c2924eb9b80d9dd250cf56a1140af157, <5.15, 6.6.157, 56af5e749f20c3a540310c207dcc373f4f09156e, 7.2.6, 5.15, <=6.18.*, 6.12.110, <=7.2.*, <1719865b20b22c88d2a55e922eff5ca31b0841f6, <e8a2027b7e686784a69b2dfcee841d779919f313, <=*, <=5.15.*, <985a37781ade19061400100c2ba0f43979dd4d63, 7.3

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_skbmod: fix length calculations and avoid invalid header warnings syzbot reported a warning in skb_network_header_len() triggered by tcf_skbmod_act(): !skb_transport_header_was_set(skb) WARNING: CPU: 0 PID: 14949 at include/linux/skbuff.h:3243 skb_network_header_len include/linux/skbuff.h:3243 [inline] WARNING: CPU: 0 PID: 14949 at net/sched/act_skbmod.c:55 tcf_skbmod_act+0xfe8/0x1810 net/sched/act_skbmod.c:55 There are a few issues in tcf_skbmod_act(): 1. Calling skb_network_header_len() assumes skb->transport_header is set, which is not guaranteed when tcf_skbmod_act() runs at TC ingress. 2. Unconditionally calling skb_mac_header_len() at the beginning of tcf_skbmod_act() triggers a warning on L3 devices (e.g. TUN) where the MAC header is unset, evaluating to an underflowed garbage length. 3. On TC ingress, skb->data points to the network header. Adding the MAC header length to the IP header length causes skb_ensure_writable() to request more bytes than the actual IP packet length, dropping valid short packets (e.g. 28-byte UDP/IPv4 packets). Fix these by: - Using skb_network_offset(skb) + sizeof(struct iphdr/ipv6hdr) for SKBMOD_F_ECN so that the required length is correctly calculated on both ingress (offset == 0) and egress (offset == mac_len). - Setting max_edit_len to ETH_HLEN for Ethernet header modifications after validating ARPHRD_ETHER.

Gravité et risque d'exploitation

CVE-2026-90078 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.21 %, ce qui la place devant 10.0 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <d896843d8d925f0adbba319020595cfb1a7bcd57, <=6.12.*, 5.15.221, 0, 6.1.188, 6.18.52, <81d0d1e64f30d9989c829c0953cd6e6c68d9c5fb, <62126464f3a6159c0a3dd89e196ba65bfeb0afc6, <=6.6.*, <0675cff3c2924eb9b80d9dd250cf56a1140af157, <5.15, 6.6.157, 56af5e749f20c3a540310c207dcc373f4f09156e, 7.2.6, 5.15, <=6.18.*, 6.12.110, <=7.2.*, <1719865b20b22c88d2a55e922eff5ca31b0841f6, <e8a2027b7e686784a69b2dfcee841d779919f313, <=*, <=5.15.*, <985a37781ade19061400100c2ba0f43979dd4d63, 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