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Unrated severityNVD Advisory· Published Feb 27, 2025· Updated Nov 3, 2025

batman-adv: fix panic during interface removal

CVE-2025-21781

Description

In the Linux kernel, the following vulnerability has been resolved:

batman-adv: fix panic during interface removal

Reference counting is used to ensure that batadv_hardif_neigh_node and batadv_hard_iface are not freed before/during batadv_v_elp_throughput_metric_update work is finished.

But there isn't a guarantee that the hard if will remain associated with a soft interface up until the work is finished.

This fixes a crash triggered by reboot that looks like this:

Call trace: batadv_v_mesh_free+0xd0/0x4dc [batman_adv] batadv_v_elp_throughput_metric_update+0x1c/0xa4 process_one_work+0x178/0x398 worker_thread+0x2e8/0x4d0 kthread+0xd8/0xdc ret_from_fork+0x10/0x20

(the batadv_v_mesh_free call is misleading, and does not actually happen)

I was able to make the issue happen more reliably by changing hardif_neigh->bat_v.metric_work work to be delayed work. This allowed me to track down and confirm the fix.

[sven@narfation.org: prevent entering batadv_v_elp_get_throughput without soft_iface]

Affected products

65

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

8

News mentions

0

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