team: fix header_ops type confusion with non-Ethernet ports
Affects Linux kernel team device setups with a non-Ethernet port, such as gre over bond over team. Fixed in 6.6.145, 6.12.80, 6.18.21 and 6.19.11.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 6.6.145, 6.12.80, 6.18.21, 6.19.11
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
3.7
- KernelLinux
From 3.7.0 · fixed in 6.6.145; From 6.7.0 · fixed in 6.12.80; From 6.13.0 · fixed in 6.18.21; From 6.19.0 · fixed in 6.19.11
References 6
git.kernel.org
Questions about CVE-2026-31502
What does this mean?
The team driver copies header callbacks from a non-Ethernet port onto the team device. When a team device calls those callbacks with the wrong net_device, the type confusion can crash the kernel.Source: git.kernel.org
Am I affected, and how do I check?
Linux kernel versions from 3.7.0 up to 6.6.145, from 6.7.0 up to 6.12.80, from 6.13.0 up to 6.18.21, and from 6.19.0 up to 6.19.11. The setup involves a team device with a non-Ethernet port, such as a gre over bond over team stack; running uname -r shows the kernel version, and ip link shows the stacked devices.Source: git.kernel.org
What should I do about it?
Upgrade to a fixed kernel for your branch: 6.6.145, 6.12.80, 6.18.21, 6.19.11, or a later release.Source: git.kernel.org
Is it being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data