Vulnerability in Linux

CVE-2025-21781

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]

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (11.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 11.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21781: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions c833484e5f3872a38fe232c663586069d5ad9645, 4.6, 0
  • Linux Kernel — versions 6.14

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21781?
CVE-2025-21781 is a medium-severity vulnerability in Linux. CVSS score: 5.5/10. Published 2025-02-27.
How severe is CVE-2025-21781?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2025-21781 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.