CVE-2025-21781

batman-adv: fix panic during interface removal

MEDIUM

5.5

CVSS Score

Published: February 27, 2025 at 02:18 AM UTC

Updated: June 17, 2026 at 08:44 AM UTC

1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

MEDIUM5.5

Exploit prediction

EPSS 0.2%

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. [[email protected]: prevent entering batadv_v_elp_get_throughput without soft_iface]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

95%

4.6 ≤ v < 5.10.2354.6 ≤ v < 5.15.1794.6 ≤ v < 5.4.2914.6 ≤ v < 6.1.1294.6 ≤ v < 6.12.164.6 ≤ v < 6.13.44.6 ≤ v < 6.144.6 ≤ v < 6.6.795.11 ≤ v < 5.15.1795.16 ≤ v < 6.1.1295.5 ≤ v < 5.10.2356.13 ≤ v < 6.13.46.2 ≤ v < 6.6.796.7 ≤ v < 6.12.164.6 6.14 rc1 6.14 rc2c833484e5f3872a38fe232c663586069d5ad9645

Vendor states this is fixed in 072b2787321903287a126c148e8db87dd7ef96fe (fixed)

Vendor states this is fixed in 167422a07096a6006599067c8b55884064fa0b72 (fixed)

Vendor states this is fixed in 2c3fb7df4cc6d043f70d4a8a10f8b915bbfb75e7 (fixed)

Vendor states this is fixed in 522b1596ea19e327853804da2de60aeb9c5d6f42 (fixed)

Vendor states this is fixed in 7eb5dd201695645af071592a50026eb780081a72 (fixed)

Vendor states this is fixed in ccb7276a6d26d6f8416e315b43b45e15ee7f29e2 (fixed)

Vendor states this is fixed in ce3f1545bf8fa28bd05ec113679e8e6cd23af577 (fixed)

Vendor states this is fixed in f0a16c6c79768180333f3e41ce63f32730e3c3af (fixed)

Vendor states this is fixed in 4.6 (unaffected)

Vendor states this is fixed in 5.10.235 (unaffected)

Vendor states this is fixed in 5.15.179 (unaffected)

Vendor states this is fixed in 5.4.291 (unaffected)