CVE-2026-46233: batman-adv: bla: only purge non-released claims

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-28 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: only purge non-released claims When batadv_bla_purge_claims() goes through the list of claims, it is only traversing the hash list with an rcu_read_lock(). Due to a potential parallel batadv_claim_put(), it can happen that it encounters a claim which was actually in the process of being released+freed by batadv_claim_release(). In this case, backbone_gw is set to NULL before the delayed RCU kfree is started. Calling batadv_bla_claim_get_backbone_gw() is then no longer allowed because it would cause a NULL-ptr derefence. To avoid this, only claims with a valid reference counter must be purged. All others are already taken care of.

Affected products

Linux kernel: from 3.5 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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