CVE-2026-43094 ixgbevf: add missing negotiate_features op to Hyper-V ops table
A missing function pointer in the ixgbevf driver causes a kernel crash on Hyper-V VMs during device probe, 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-2026-43094?
CVE-2026-43094 is a medium-severity vulnerability in Linux kernel, published on 6 May 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:
ixgbevf: add missing negotiate_features op to Hyper-V ops table
Commit a7075f501bd3 ("ixgbevf: fix mailbox API compatibility by negotiating supported features") added the .negotiate_features callback to ixgbe_mac_operations and populated it in ixgbevf_mac_ops, but forgot to add it to ixgbevf_hv_mac_ops. This leaves the function pointer NULL on Hyper-V VMs.
During probe, ixgbevf_negotiate_api() calls ixgbevf_set_features(), which unconditionally dereferences hw->mac.ops.negotiate_features(). On Hyper-V this results in a NULL pointer dereference:
BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine [...] Workqueue: events work_for_cpu_fn RIP: 0010:0x0 [...] Call Trace: ixgbevf_negotiate_api+0x66/0x160 [ixgbevf] ixgbevf_sw_init+0xe4/0x1f0 [ixgbevf] ixgbevf_probe+0x20f/0x4a0 [ixgbevf] local_pci_probe+0x50/0xa0 work_for_cpu_fn+0x1a/0x30 [...]
Add ixgbevf_hv_negotiate_features_vf() that returns -EOPNOTSUPP and wire it into ixgbevf_hv_mac_ops. The caller already handles -EOPNOTSUPP gracefully.
Weakness: CWE-476
Which versions are affected by CVE-2026-43094?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43094?
Apply the vendor's patch.
Is CVE-2026-43094 being exploited?
There is no known exploitation of CVE-2026-43094 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43094, DEBIAN-CVE-2026-43094, GHSA-8c3v-5v6w-588p, ROOT-OS-DEBIAN-12-CVE-2026-43094, ROOT-OS-UBUNTU-2404-CVE-2026-43094, UBUNTU-CVE-2026-43094.