<Vulnerability name="CVE-2026-31695">
    <DocumentDistribution xml:lang="en">Copyright © 2012 Red Hat, Inc. All rights reserved.</DocumentDistribution>
    <PublicDate>2026-05-01T00:00:00</PublicDate>
    <Bugzilla id="2464466" url="https://bugzilla.redhat.com/show_bug.cgi?id=2464466" xml:lang="en:us">
kernel: wifi: virt_wifi: remove SET_NETDEV_DEV to avoid use-after-free
    </Bugzilla>
    <CWE>CWE-825</CWE>
    <Details xml:lang="en:us" source="Mitre">
In the Linux kernel, the following vulnerability has been resolved:

wifi: virt_wifi: remove SET_NETDEV_DEV to avoid use-after-free

Currently we execute `SET_NETDEV_DEV(dev, &amp;priv-&gt;lowerdev-&gt;dev)` for
the virt_wifi net devices. However, unregistering a virt_wifi device in
netdev_run_todo() can happen together with the device referenced by
SET_NETDEV_DEV().

It can result in use-after-free during the ethtool operations performed
on a virt_wifi device that is currently being unregistered. Such a net
device can have the `dev.parent` field pointing to the freed memory,
but ethnl_ops_begin() calls `pm_runtime_get_sync(dev-&gt;dev.parent)`.

Let's remove SET_NETDEV_DEV for virt_wifi to avoid bugs like this:

 ==================================================================
 BUG: KASAN: slab-use-after-free in __pm_runtime_resume+0xe2/0xf0
 Read of size 2 at addr ffff88810cfc46f8 by task pm/606

 Call Trace:
  &lt;TASK&gt;
  dump_stack_lvl+0x4d/0x70
  print_report+0x170/0x4f3
  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
  kasan_report+0xda/0x110
  ? __pm_runtime_resume+0xe2/0xf0
  ? __pm_runtime_resume+0xe2/0xf0
  __pm_runtime_resume+0xe2/0xf0
  ethnl_ops_begin+0x49/0x270
  ethnl_set_features+0x23c/0xab0
  ? __pfx_ethnl_set_features+0x10/0x10
  ? kvm_sched_clock_read+0x11/0x20
  ? local_clock_noinstr+0xf/0xf0
  ? local_clock+0x10/0x30
  ? kasan_save_track+0x25/0x60
  ? __kasan_kmalloc+0x7f/0x90
  ? genl_family_rcv_msg_attrs_parse.isra.0+0x150/0x2c0
  genl_family_rcv_msg_doit+0x1e7/0x2c0
  ? __pfx_genl_family_rcv_msg_doit+0x10/0x10
  ? __pfx_cred_has_capability.isra.0+0x10/0x10
  ? stack_trace_save+0x8e/0xc0
  genl_rcv_msg+0x411/0x660
  ? __pfx_genl_rcv_msg+0x10/0x10
  ? __pfx_ethnl_set_features+0x10/0x10
  netlink_rcv_skb+0x121/0x380
  ? __pfx_genl_rcv_msg+0x10/0x10
  ? __pfx_netlink_rcv_skb+0x10/0x10
  ? __pfx_down_read+0x10/0x10
  genl_rcv+0x23/0x30
  netlink_unicast+0x60f/0x830
  ? __pfx_netlink_unicast+0x10/0x10
  ? __pfx___alloc_skb+0x10/0x10
  netlink_sendmsg+0x6ea/0xbc0
  ? __pfx_netlink_sendmsg+0x10/0x10
  ? __futex_queue+0x10b/0x1f0
  ____sys_sendmsg+0x7a2/0x950
  ? copy_msghdr_from_user+0x26b/0x430
  ? __pfx_____sys_sendmsg+0x10/0x10
  ? __pfx_copy_msghdr_from_user+0x10/0x10
  ___sys_sendmsg+0xf8/0x180
  ? __pfx____sys_sendmsg+0x10/0x10
  ? __pfx_futex_wait+0x10/0x10
  ? fdget+0x2e4/0x4a0
  __sys_sendmsg+0x11f/0x1c0
  ? __pfx___sys_sendmsg+0x10/0x10
  do_syscall_64+0xe2/0x570
  ? exc_page_fault+0x66/0xb0
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
  &lt;/TASK&gt;

This fix may be combined with another one in the ethtool subsystem:
https://lore.kernel.org/all/20260322075917.254874-1-alex.popov@linux.com/T/#u
    </Details>
    <Details xml:lang="en:us" source="Red Hat">
A flaw was found in the Linux kernel's virt_wifi component. A local user can exploit a race condition during the unregistration of a virt_wifi network device, where its parent pointer might refer to freed memory during ethtool operations. This use-after-free vulnerability can lead to system instability or a denial of service.
    </Details>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:10">
        <ProductName>Red Hat Enterprise Linux 10</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:6">
        <ProductName>Red Hat Enterprise Linux 6</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:7">
        <ProductName>Red Hat Enterprise Linux 7</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:7">
        <ProductName>Red Hat Enterprise Linux 7</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:8">
        <ProductName>Red Hat Enterprise Linux 8</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:8">
        <ProductName>Red Hat Enterprise Linux 8</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:9">
        <ProductName>Red Hat Enterprise Linux 9</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel</PackageName>
    </PackageState>
    <PackageState cpe="cpe:/o:redhat:enterprise_linux:9">
        <ProductName>Red Hat Enterprise Linux 9</ProductName>
        <FixState>Not affected</FixState>
        <PackageName>kernel-rt</PackageName>
    </PackageState>
    <References xml:lang="en:us">
https://www.cve.org/CVERecord?id=CVE-2026-31695
https://nvd.nist.gov/vuln/detail/CVE-2026-31695
https://lore.kernel.org/linux-cve-announce/2026050141-CVE-2026-31695-813b@gregkh/T
    </References>
</Vulnerability>