linux-cve-announce - CVE-2026-22981: idpf: detach and close netdevs while handling a reset

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Message-ID: <2026012348-CVE-2026-22981-94c5@gregkh>
Date: Fri, 23 Jan 2026 16:24:52 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2026-22981: idpf: detach and close netdevs while handling a reset

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

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

idpf: detach and close netdevs while handling a reset

Protect the reset path from callbacks by setting the netdevs to detached
state and close any netdevs in UP state until the reset handling has
completed. During a reset, the driver will de-allocate resources for the
vport, and there is no guarantee that those will recover, which is why the
existing vport_ctrl_lock does not provide sufficient protection.

idpf_detach_and_close() is called right before reset handling. If the
reset handling succeeds, the netdevs state is recovered via call to
idpf_attach_and_open(). If the reset handling fails the netdevs remain
down. The detach/down calls are protected with RTNL lock to avoid racing
with callbacks. On the recovery side the attach can be done without
holding the RTNL lock as there are no callbacks expected at that point,
due to detach/close always being done first in that flow.

The previous logic restoring the netdevs state based on the
IDPF_VPORT_UP_REQUESTED flag in the init task is not needed anymore, hence
the removal of idpf_set_vport_state(). The IDPF_VPORT_UP_REQUESTED is
still being used to restore the state of the netdevs following the reset,
but has no use outside of the reset handling flow.

idpf_init_hard_reset() is converted to void, since it was used as such and
there is no error handling being done based on its return value.

Before this change, invoking hard and soft resets simultaneously will
cause the driver to lose the vport state:
ip -br a
<inf>	UP
echo 1 > /sys/class/net/ens801f0/device/reset& \
ethtool -L ens801f0 combined 8
ip -br a
<inf>	DOWN
ip link set <inf> up
ip -br a
<inf>	DOWN

Also in case of a failure in the reset path, the netdev is left
exposed to external callbacks, while vport resources are not
initialized, leading to a crash on subsequent ifup/down:
[408471.398966] idpf 0000:83:00.0: HW reset detected
[408471.411744] idpf 0000:83:00.0: Device HW Reset initiated
[408472.277901] idpf 0000:83:00.0: The driver was unable to contact the device's firmware. Check that the FW is running. Driver state= 0x2
[408508.125551] BUG: kernel NULL pointer dereference, address: 0000000000000078
[408508.126112] #PF: supervisor read access in kernel mode
[408508.126687] #PF: error_code(0x0000) - not-present page
[408508.127256] PGD 2aae2f067 P4D 0
[408508.127824] Oops: Oops: 0000 [#1] SMP NOPTI
...
[408508.130871] RIP: 0010:idpf_stop+0x39/0x70 [idpf]
...
[408508.139193] Call Trace:
[408508.139637]  <TASK>
[408508.140077]  __dev_close_many+0xbb/0x260
[408508.140533]  __dev_change_flags+0x1cf/0x280
[408508.140987]  netif_change_flags+0x26/0x70
[408508.141434]  dev_change_flags+0x3d/0xb0
[408508.141878]  devinet_ioctl+0x460/0x890
[408508.142321]  inet_ioctl+0x18e/0x1d0
[408508.142762]  ? _copy_to_user+0x22/0x70
[408508.143207]  sock_do_ioctl+0x3d/0xe0
[408508.143652]  sock_ioctl+0x10e/0x330
[408508.144091]  ? find_held_lock+0x2b/0x80
[408508.144537]  __x64_sys_ioctl+0x96/0xe0
[408508.144979]  do_syscall_64+0x79/0x3d0
[408508.145415]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[408508.145860] RIP: 0033:0x7f3e0bb4caff

The Linux kernel CVE team has assigned CVE-2026-22981 to this issue.


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

	Issue introduced in 6.7 with commit 0fe45467a1041ea3657a7fa3a791c84c104fbd34 and fixed in 6.18.6 with commit ac122f5fb050903b3d262001562c452be95eaf70
	Issue introduced in 6.7 with commit 0fe45467a1041ea3657a7fa3a791c84c104fbd34 and fixed in 6.19-rc5 with commit 2e281e1155fc476c571c0bd2ffbfe28ab829a5c3

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-2026-22981
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_lib.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/ac122f5fb050903b3d262001562c452be95eaf70
	https://git.kernel.org/stable/c/2e281e1155fc476c571c0bd2ffbfe28ab829a5c3