CVE-2025-21781

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Source
https://cve.org/CVERecord?id=CVE-2025-21781
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21781.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2025-21781
Downstream
Related
Published
2025-02-27T02:18:24Z
Modified
2026-08-12T03:30:19Z
Summary
batman-adv: fix panic during interface removal
Details

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]

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21781.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
c833484e5f3872a38fe232c663586069d5ad9645
Fixed
167422a07096a6006599067c8b55884064fa0b72
Fixed
ce3f1545bf8fa28bd05ec113679e8e6cd23af577
Fixed
f0a16c6c79768180333f3e41ce63f32730e3c3af
Fixed
7eb5dd201695645af071592a50026eb780081a72
Fixed
072b2787321903287a126c148e8db87dd7ef96fe
Fixed
2c3fb7df4cc6d043f70d4a8a10f8b915bbfb75e7
Fixed
522b1596ea19e327853804da2de60aeb9c5d6f42
Fixed
ccb7276a6d26d6f8416e315b43b45e15ee7f29e2

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21781.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
4.6.0
Fixed
5.4.291
Type
ECOSYSTEM
Events
Introduced
5.5.0
Fixed
5.10.235
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.179
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.129
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.79
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.16
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.13.4

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21781.json"