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

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Message-ID: <2026012349-CVE-2026-22985-9a80@gregkh>
Date: Fri, 23 Jan 2026 16:24:56 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2026-22985: idpf: Fix RSS LUT NULL pointer crash on early ethtool operations

From: Greg Kroah-Hartman <gregkh@...nel.org>

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>

The Linux kernel CVE team has assigned CVE-2026-22985 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.7 with commit a251eee62133774cf35ff829041377e721ef9c8c and fixed in 6.18.6 with commit b29a5a7dd1f4293ee49c469938c25bf85a5aa802
	Issue introduced in 6.7 with commit a251eee62133774cf35ff829041377e721ef9c8c and fixed in 6.19-rc5 with commit 83f38f210b85676f40ba8586b5a8edae19b56995

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-22985
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/intel/idpf/idpf.h
	drivers/net/ethernet/intel/idpf/idpf_lib.c
	drivers/net/ethernet/intel/idpf/idpf_txrx.c
	drivers/net/ethernet/intel/idpf/idpf_txrx.h
	drivers/net/ethernet/intel/idpf/idpf_virtchnl.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/b29a5a7dd1f4293ee49c469938c25bf85a5aa802
	https://git.kernel.org/stable/c/83f38f210b85676f40ba8586b5a8edae19b56995