GHSA-89j4-f3cq-gm32

Опубликовано: 14 фев. 2026

Источник: github

Github: Не прошло ревью

CVSS3: 7.8

Описание

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

macvlan: fix error recovery in macvlan_common_newlink()

valis provided a nice repro to crash the kernel:

ip link add p1 type veth peer p2 ip link set address 00:00:00:00:00:20 dev p1 ip link set up dev p1 ip link set up dev p2

ip link add mv0 link p2 type macvlan mode source ip link add invalid% link p2 type macvlan mode source macaddr add 00:00:00:00:00:20

ping -c1 -I p1 1.2.3.4

He also gave a very detailed analysis:

The issue is triggered when a new macvlan link is created with MACVLAN_MODE_SOURCE mode and MACVLAN_MACADDR_ADD (or MACVLAN_MACADDR_SET) parameter, lower device already has a macvlan port and register_netdevice() called from macvlan_common_newlink() fails (e.g. because of the invalid link name).

In this case macvlan_hash_add_source is called from macvlan_change_sources() / macvlan_common_newlink():

This adds a reference to vlan to the port's vlan_source_hash using macvlan_sourc...

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

macvlan: fix error recovery in macvlan_common_newlink()

valis provided a nice repro to crash the kernel:

ip link add p1 type veth peer p2 ip link set address 00:00:00:00:00:20 dev p1 ip link set up dev p1 ip link set up dev p2

ip link add mv0 link p2 type macvlan mode source ip link add invalid% link p2 type macvlan mode source macaddr add 00:00:00:00:00:20

ping -c1 -I p1 1.2.3.4

He also gave a very detailed analysis:

In this case macvlan_hash_add_source is called from macvlan_change_sources() / macvlan_common_newlink():

This adds a reference to vlan to the port's vlan_source_hash using macvlan_source_entry.

vlan is a pointer to the priv data of the link that is being created.

When register_netdevice() fails, the error is returned from macvlan_newlink() to rtnl_newlink_create():

if (ops->newlink) err = ops->newlink(dev, &params, extack); else err = register_netdevice(dev); if (err < 0) { free_netdev(dev); goto out; }

and free_netdev() is called, causing a kvfree() on the struct net_device that is still referenced in the source entry attached to the lower device's macvlan port.

Now all packets sent on the macvlan port with a matching source mac address will trigger a use-after-free in macvlan_forward_source().

</quote valis>

With all that, my fix is to make sure we call macvlan_flush_sources() regardless of @create value whenever "goto destroy_macvlan_port;" path is taken.

Many thanks to valis for following up on this issue.

Ссылки

EPSS

Процентиль: 2%

0.00014

Низкий

7.8 High

CVSS3

CVE ID

CVE-2026-23209

Дефекты

CWE-416

Связанные уязвимости

CVE-2026-23209

CVSS3: 7.8

ubuntu

около 1 месяца назад

In the Linux kernel, the following vulnerability has been resolved: macvlan: fix error recovery in macvlan_common_newlink() valis provided a nice repro to crash the kernel: ip link add p1 type veth peer p2 ip link set address 00:00:00:00:00:20 dev p1 ip link set up dev p1 ip link set up dev p2 ip link add mv0 link p2 type macvlan mode source ip link add invalid% link p2 type macvlan mode source macaddr add 00:00:00:00:00:20 ping -c1 -I p1 1.2.3.4 He also gave a very detailed analysis: <quote valis> The issue is triggered when a new macvlan link is created with MACVLAN_MODE_SOURCE mode and MACVLAN_MACADDR_ADD (or MACVLAN_MACADDR_SET) parameter, lower device already has a macvlan port and register_netdevice() called from macvlan_common_newlink() fails (e.g. because of the invalid link name). In this case macvlan_hash_add_source is called from macvlan_change_sources() / macvlan_common_newlink(): This adds a reference to vlan to the port's vlan_source_hash using macvlan_source_entry. v...