CVE-2026-22994 bpf: Fix reference count leak in bpf_prog_test_run_xdp()
A reference count leak in the Linux kernel's BPF test run function can cause network devices to hang, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-22994?
CVE-2026-22994 is a medium-severity denial of service vulnerability in Linux kernel, published on 23 Jan 2026. 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:
bpf: Fix reference count leak in bpf_prog_test_run_xdp()
syzbot is reporting
unregister_netdevice: waiting for sit0 to become free. Usage count = 2
problem. A debug printk() patch found that a refcount is obtained at xdp_convert_md_to_buff() from bpf_prog_test_run_xdp().
According to commit ec94670fcb3b ("bpf: Support specifying ingress via xdp_md context in BPF_PROG_TEST_RUN"), the refcount obtained by xdp_convert_md_to_buff() will be released by xdp_convert_buff_to_md().
Therefore, we can consider that the error handling path introduced by commit 1c1949982524 ("bpf: introduce frags support to bpf_prog_test_run_xdp()") forgot to call xdp_convert_buff_to_md().
Which versions are affected by CVE-2026-22994?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-22994?
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-2026-22994 being exploited?
There is no known exploitation of CVE-2026-22994 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-22994, DEBIAN-CVE-2026-22994, GHSA-8r55-jh7v-855p, ROOT-OS-DEBIAN-12-CVE-2026-22994, ROOT-OS-DEBIAN-13-CVE-2026-22994, ROOT-OS-UBUNTU-2404-CVE-2026-22994 and 1 more.