CVE-2026-22985 idpf: Fix RSS LUT NULL pointer crash on early ethtool operations

Medium 5.5 Published 23 Jan 2026 Updated 11 May 2026

A local attacker can crash the Linux kernel by disabling rxhash on an Intel idpf network interface before it is brought up.

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-2026-22985?

CVE-2026-22985 is a medium-severity 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:

idpf: Fix RSS LUT NULL pointer crash on early ethtool operations

The RSS LUT is not initialized until the interface comes up, causing the following NULL pointer crash when ethtool operations like rxhash on/off are performed before the interface is brought up for the first time.

Move RSS LUT initialization from ndo_open to vport creation to ensure LUT is always available. This enables RSS configuration via ethtool before bringing the interface up. Simplify LUT management by maintaining all changes in the driver's soft copy and programming zeros to the indirection table when rxhash is disabled. Defer HW programming until the interface comes up if it is down during rxhash and LUT configuration changes.

Steps to reproduce: ** Load idpf driver; interfaces will be created modprobe idpf ** Before bringing the interfaces up, turn rxhash off ethtool -K eth2 rxhash off

[89408.371875] BUG: kernel NULL pointer dereference, address: 0000000000000000 [89408.371908] #PF: supervisor read access in kernel mode [89408.371924] #PF: error_code(0x0000) - not-present page [89408.371940] PGD 0 P4D 0 [89408.371953] Oops: Oops: 0000 [#1] SMP NOPTI <snip> [89408.372052] RIP: 0010:memcpy_orig+0x16/0x130 [89408.372310] Call Trace: [89408.372317] <TASK> [89408.372326] ? idpf_set_features+0xfc/0x180 [idpf] [89408.372363] __netdev_update_features+0x295/0xde0 [89408.372384] ethnl_set_features+0x15e/0x460 [89408.372406] genl_family_rcv_msg_doit+0x11f/0x180 [89408.372429] genl_rcv_msg+0x1ad/0x2b0 [89408.372446] ? __pfx_ethnl_set_features+0x10/0x10 [89408.372465] ? __pfx_genl_rcv_msg+0x10/0x10 [89408.372482] netlink_rcv_skb+0x58/0x100 [89408.372502] genl_rcv+0x2c/0x50 [89408.372516] netlink_unicast+0x289/0x3e0 [89408.372533] netlink_sendmsg+0x215/0x440 [89408.372551] __sys_sendto+0x234/0x240 [89408.372571] __x64_sys_sendto+0x28/0x30 [89408.372585] x64_sys_call+0x1909/0x1da0 [89408.372604] do_syscall_64+0x7a/0xfa0 [89408.373140] ? clear_bhb_loop+0x60/0xb0 [89408.373647] entry_SYSCALL_64_after_hwframe+0x76/0x7e [89408.378887] </TASK> <snip>

Weakness: CWE-476

Which versions are affected by CVE-2026-22985?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-22985?

Apply the vendor's patch.

Is CVE-2026-22985 being exploited?

There is no known exploitation of CVE-2026-22985 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-22985, DEBIAN-CVE-2026-22985, GHSA-gj4p-f535-7c3j, ROOT-OS-DEBIAN-13-CVE-2026-22985, ROOT-OS-UBUNTU-2404-CVE-2026-22985, UBUNTU-CVE-2026-22985.