CVE-2025-68216 LoongArch: BPF: Disable trampoline for kernel module function trace
A local attacker with high privileges can cause kernel lockups or traffic disruption by attaching BPF programs to kernel module functions on LoongArch systems.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68216?
CVE-2025-68216 is a denial of service vulnerability in Linux, published on 16 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: BPF: Disable trampoline for kernel module function trace
The current LoongArch BPF trampoline implementation is incompatible with tracing functions in kernel modules. This causes several severe and user-visible problems:
* The `bpf_selftests/module_attach` test fails consistently. * Kernel lockup when a BPF program is attached to a module function [1]. * Critical kernel modules like WireGuard experience traffic disruption when their functions are traced with fentry [2].
Given the severity and the potential for other unknown side-effects, it is safest to disable the feature entirely for now. This patch prevents the BPF subsystem from allowing trampoline attachments to kernel module functions on LoongArch.
This is a temporary mitigation until the core issues in the trampoline code for kernel module handling can be identified and fixed.
[root@fedora bpf]# ./test_progs -a module_attach -v bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_module_attach:PASS:skel_open 0 nsec test_module_attach:PASS:set_attach_target 0 nsec test_module_attach:PASS:set_attach_target_explicit 0 nsec test_module_attach:PASS:skel_load 0 nsec libbpf: prog 'handle_fentry': failed to attach: -ENOTSUPP libbpf: prog 'handle_fentry': failed to auto-attach: -ENOTSUPP test_module_attach:FAIL:skel_attach skeleton attach failed: -524 Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED Successfully unloaded bpf_testmod.ko.
[1]: https://lore.kernel.org/loongarch/CAK3+h2wDmpC-hP4u4pJY8T-yfKyk4yRzpu2LMO+C13FMT58oqQ@mail.gmail.com/ [2]: https://lore.kernel.org/loongarch/CAK3+h2wYcpc+OwdLDUBvg2rF9rvvyc5amfHT-KcFaK93uoELPg@mail.gmail.com/
Which versions are affected by CVE-2025-68216?
How do I fix CVE-2025-68216?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-68216 being exploited?
There is no known exploitation of CVE-2025-68216 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68216, DEBIAN-CVE-2025-68216, GHSA-gvc4-65gw-vx8r, UBUNTU-CVE-2025-68216.