CVE-2025-21781
MediumIn 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. [[email protected]: prevent entering batadv_v_elp_get_throughput without soft_iface]
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Affected versions
Linux kernel versions
4.6
and later are affected. Fixed in
5.4.291,
5.10.235,
5.15.179,
6.1.129,
6.6.79,
6.12.16,
6.13.4,
6.14
and their respective stable series.
References
The following references provide additional information about CVE-2025-21781 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/072b2787321903287a126c148e8db87dd7ef96fe
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PatchKernel patch commithttps://git.kernel.org/stable/c/167422a07096a6006599067c8b55884064fa0b72
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PatchKernel patch commithttps://git.kernel.org/stable/c/2c3fb7df4cc6d043f70d4a8a10f8b915bbfb75e7
Frequently asked questions
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What is CVE-2025-21781?
CVE-2025-21781 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 4.6 onward and has been patched in 5.4.291, 5.10.235, 5.15.179 and others. CVE-2025-21781 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2025-21781?
CVE-2025-21781 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2025-21781?
Yes — CVE-2025-21781 has been patched. Fixed versions include 5.4.291, 5.10.235, 5.15.179 and others. If you are running Linux kernel 4.6 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-21781 actively exploited?
No — CVE-2025-21781 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.