CVE-2026-46233
Received Received - Intake
Memory Leak in Linux Kernel batman-adv BLA Component

Publication date: 2026-05-28

Last updated on: 2026-05-28

Assigner: kernel.org

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.
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Meta Information
Published
2026-05-28
Last Modified
2026-05-28
Generated
2026-05-28
AI Q&A
2026-05-28
EPSS Evaluated
N/A
NVD
EUVD
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's batman-adv component, specifically in the handling of claims within the bla (batadv_bla) module.

The function batadv_bla_purge_claims() traverses a list of claims using an rcu_read_lock(). However, due to concurrent operations by batadv_claim_put(), it may encounter a claim that is in the process of being released and freed by batadv_claim_release().

In such cases, the backbone_gw pointer is set to NULL before the delayed RCU kfree is executed. If batadv_bla_claim_get_backbone_gw() is called on such a claim, it results in a NULL pointer dereference, causing a potential crash or undefined behavior.

The fix ensures that only claims with a valid reference counter are purged, preventing access to claims that are already being freed.


How can this vulnerability impact me? :

This vulnerability can lead to a NULL pointer dereference in the Linux kernel's batman-adv module.

Such a NULL pointer dereference can cause the kernel to crash or behave unpredictably, potentially leading to denial of service (DoS) conditions on affected systems.

Systems relying on the batman-adv module for mesh networking or related functionality may experience instability or outages due to this issue.


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