CVE-2026-46238: batman-adv: stop caching unowned originator pointers in BAT IV

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-28 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: stop caching unowned originator pointers in BAT IV BAT IV keeps the last-hop neighbor address in each neigh_node, but some paths also cache an originator pointer derived from a temporary lookup. That pointer is not owned by the neigh_node and may no longer refer to a live originator entry after purge handling runs. Stop storing the auxiliary originator pointer in the BAT IV neighbor state. When BAT IV needs the neighbor originator data, resolve it from the stored neighbor address and drop the reference again after use. [sven: avoid bonding logic for outgoing OGM]

Affected products

Linux kernel: from 2.6.38 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.140; from 6.7 before 6.12.90; from 6.13 before 6.18.32 — fixed in 5.10.258, 5.15.209, 6.1.175, 6.12.90, 6.18.32, 6.6.140

How to fix

Upgrade to a fixed version: Linux kernel 5.10.258, 5.15.209, 6.1.175, 6.12.90. Check the vendor advisory for mitigations.

References

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