Bug 2502238 (CVE-2026-63835)

Summary: CVE-2026-63835 kernel: batman-adv: v: prevent OGM aggregation on disabled hardif
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Better Approach To Mobile Ad-hoc Networking (batman-adv) module. When a batman-adv interface is disabled, the system can still queue network packets (skbs) for aggregation. These packets are not properly freed, leading to a memory leak. This can result in resource exhaustion and a Denial of Service (DoS) condition for the system.
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Description OSIDB Bzimport 2026-07-19 13:03:25 UTC 
In the Linux kernel, the following vulnerability has been resolved:

batman-adv: v: prevent OGM aggregation on disabled hardif

When an interface gets disabled, the worker is correctly disabled by
batadv_hardif_disable_interface() -> ... -> batadv_v_ogm_iface_disable().
In this process, the skb aggr_list is also freed.

But batadv_v_ogm_send_meshif() can still queue new skbs (via
batadv_v_ogm_queue_on_if()) to the aggr_list. This will only stop after all
cores can no longer find the RCU protected list of hard interfaces. These
queued skbs will never be freed or consumed by batadv_v_ogm_aggr_work.

The batadv_v_ogm_iface_disable() function must block
batadv_v_ogm_queue_on_if() to avoid leak of skbs.
Comment 1 Keith Grant 2026-07-20 16:45:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026071909-CVE-2026-63835-5915@gregkh/T