CVE-2021-47517

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Source
https://nvd.nist.gov/vuln/detail/CVE-2021-47517
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47517.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2021-47517
Related
Published
2024-05-24T15:15:13Z
Modified
2024-09-18T03:18:51.317318Z
Summary
[none]
Details

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

ethtool: do not perform operations on net devices being unregistered

There is a short period between a net device starts to be unregistered and when it is actually gone. In that time frame ethtool operations could still be performed, which might end up in unwanted or undefined behaviours[1].

Do not allow ethtool operations after a net device starts its unregistration. This patch targets the netlink part as the ioctl one isn't affected: the reference to the net device is taken and the operation is executed within an rtnl lock section and the net device won't be found after unregister.

[1] For example adding Tx queues after unregister ends up in NULL pointer exceptions and UaFs, such as:

  BUG: KASAN: use-after-free in kobject_get+0x14/0x90
  Read of size 1 at addr ffff88801961248c by task ethtool/755

  CPU: 0 PID: 755 Comm: ethtool Not tainted 5.15.0-rc6+ #778
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/014
  Call Trace:
   dump_stack_lvl+0x57/0x72
   print_address_description.constprop.0+0x1f/0x140
   kasan_report.cold+0x7f/0x11b
   kobject_get+0x14/0x90
   kobject_add_internal+0x3d1/0x450
   kobject_init_and_add+0xba/0xf0
   netdev_queue_update_kobjects+0xcf/0x200
   netif_set_real_num_tx_queues+0xb4/0x310
   veth_set_channels+0x1c3/0x550
   ethnl_set_channels+0x524/0x610
References

Affected packages

Debian:11 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.10.92-1

Affected versions

5.*

5.10.46-4
5.10.46-5
5.10.70-1~bpo10+1
5.10.70-1
5.10.84-1
5.10.92-1~bpo10+1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:12 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.15.15-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
5.15.15-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}