CVE-2026-31502

Description

In the Linux kernel, the following vulnerability has been resolved: team: fix header_ops type confusion with non-Ethernet ports Similar to commit 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()") team has the same class of header_ops type confusion. For non-Ethernet ports, team_setup_by_port() copies port_dev->header_ops directly. When the team device later calls dev_hard_header() or dev_parse_header(), these callbacks can run with the team net_device instead of the real lower device, so netdev_priv(dev) is interpreted as the wrong private type and can crash. The syzbot report shows a crash in bond_header_create(), but the root cause is in team: the topology is gre -> bond -> team, and team calls the inherited header_ops with its own net_device instead of the lower device, so bond_header_create() receives a team device and interprets netdev_priv() as bonding private data, causing a type confusion crash. Fix this by introducing team header_ops wrappers for create/parse, selecting a team port under RCU, and calling the lower device callbacks with port->dev, so each callback always sees the correct net_device context. Also pass the selected lower device to the lower parse callback, so recursion is bounded in stacked non-Ethernet topologies and parse callbacks always run with the correct device context.

Gravité et risque d'exploitation

CVE-2026-31502 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 0.13 %, ce qui la place devant 2.2 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.12.*, <6d3161fa3eee64d46b766fb0db33ec7f300ef52d, 0, 7.0, <=6.6.*, 6.19.11, <=6.19.*, <=6.18.*, 6.6.145, 6.12.80, <3.7, <20491d384d973a63fbdaf7a71e38d69b0659ea55, <=*, 3.7, <420e5aad7ba89e8f79e2dc8327b0c0c24c1c1d53, <425000dbf17373a4ab8be9428f5dc055ef870a56, <0a7468ed49a6b65d34abcc6eb60e15f7f6d34da0, 6.18.21, 1d76efe1577b4323609b1bcbfafa8b731eda071a) 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

• https://git.kernel.org/stable/c/420e5aad7ba89e8f79e2dc8327b0c0c24c1c1d53
• https://git.kernel.org/stable/c/6d3161fa3eee64d46b766fb0db33ec7f300ef52d
• https://git.kernel.org/stable/c/0a7468ed49a6b65d34abcc6eb60e15f7f6d34da0
• https://git.kernel.org/stable/c/20491d384d973a63fbdaf7a71e38d69b0659ea55
• https://git.kernel.org/stable/c/425000dbf17373a4ab8be9428f5dc055ef870a56