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.

CVSS Metrics

• v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.13%• Percentile: 3%

Techniques & Countermeasures

• CWE-843•Access of Resource Using Incompatible Type ('Type Confusion')

  The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

Affected Systems

• linux•linux

  ≥ 1d76efe1577b4323609b1bcbfafa8b731eda071a, < 6d3161fa3eee64d46b766fb0db33ec7f300ef52d | ≥ 1d76efe1577b4323609b1bcbfafa8b731eda071a, < 0a7468ed49a6b65d34abcc6eb60e15f7f6d34da0 | ≥ 1d76efe1577b4323609b1bcbfafa8b731eda071a, < 20491d384d973a63fbdaf7a71e38d69b0659ea55 | ≥ 1d76efe1577b4323609b1bcbfafa8b731eda071a, < 425000dbf17373a4ab8be9428f5dc055ef870a56 | 3.7

• linux•linux kernel

  ≥ 3.7.1, < 6.12.80 | ≥ 6.13, < 6.18.21 | ≥ 6.19, < 6.19.11 | 3.7 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7

References (4)

• 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