CVE-2025-68216
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/
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
LoongArch BPF trampoline disabled for module functions due to kernel crashes and test failures.
The LoongArch BPF trampoline implementation is incompatible with tracing functions in kernel modules, leading to severe issues. This causes kernel lockups and traffic disruption in critical modules like WireGuard [1]. The problem manifests when BPF programs attach to module functions via fentry, as demonstrated by the bpf_selftests/module_attach test failure [1]. An attacker with BPF permissions could exploit this to crash the system or disrupt network connectivity. As a temporary mitigation, the feature is disabled to prevent such attachments until the core issues are resolved [1].
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
2Patches
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