Описание
In the Linux kernel, the following vulnerability has been resolved:
openvswitch: Fix CT limit teardown use-after-free
Packet processing uses CT limit state under RCU, while netns teardown
frees that state under ovs_mutex. The CT limit pointer was neither removed
from readers nor protected by a grace period, allowing packet processing to
dereference the freed state.
An unprivileged user can trigger this bug from a user and network
namespace, causing a slab-use-after-free in ovs_ct_execute() when the
netns is torn down.
Publish the CT limit pointer through RCU, remove it before teardown, and
wait for readers before freeing its contents. Keep ovs_mutex around
individual CT limit updates, and use the RCU read-side lock while GET
traverses the RCU-protected limit lists.
Netns teardown detaches the RCU-protected CT limit state in the pernet
.pre_exit callback while holding ovs_mutex. The pernet core guarantees an
RCU grace period between the .pre_exit and .exit callbacks, so the .exit
callback completes the teardown without adding any extra synchronization.
The netlink command handlers do not need NULL checks because the userspace
netlink socket holds an active reference to its network namespace while a
request is processed. The per-netns exit path therefore cannot run
concurrently with SET, DEL, or GET for that socket's namespace.
A flaw was found in the Linux kernel's Open vSwitch (OVS) component. An unprivileged user, operating from a user and network namespace, can trigger a use-after-free vulnerability during network namespace teardown. This occurs because packet processing attempts to use connection tracking (CT) limit state after it has been freed, leading to a slab-use-after-free condition. This vulnerability could potentially lead to a denial of service.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Fix deferred |
Показывать по
Ссылки на источники
Дополнительная информация
Статус:
EPSS
4.7 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: openvswitch: Fix CT limit teardown use-after-free Packet processing uses CT limit state under RCU, while netns teardown frees that state under ovs_mutex. The CT limit pointer was neither removed from readers nor protected by a grace period, allowing packet processing to dereference the freed state. An unprivileged user can trigger this bug from a user and network namespace, causing a slab-use-after-free in ovs_ct_execute() when the netns is torn down. Publish the CT limit pointer through RCU, remove it before teardown, and wait for readers before freeing its contents. Keep ovs_mutex around individual CT limit updates, and use the RCU read-side lock while GET traverses the RCU-protected limit lists. Netns teardown detaches the RCU-protected CT limit state in the pernet .pre_exit callback while holding ovs_mutex. The pernet core guarantees an RCU grace period between the .pre_exit and .exit callbacks, so the .exit ca...
In the Linux kernel, the following vulnerability has been resolved: openvswitch: Fix CT limit teardown use-after-free Packet processing uses CT limit state under RCU, while netns teardown frees that state under ovs_mutex. The CT limit pointer was neither removed from readers nor protected by a grace period, allowing packet processing to dereference the freed state. An unprivileged user can trigger this bug from a user and network namespace, causing a slab-use-after-free in ovs_ct_execute() when the netns is torn down. Publish the CT limit pointer through RCU, remove it before teardown, and wait for readers before freeing its contents. Keep ovs_mutex around individual CT limit updates, and use the RCU read-side lock while GET traverses the RCU-protected limit lists. Netns teardown detaches the RCU-protected CT limit state in the pernet .pre_exit callback while holding ovs_mutex. The pernet core guarantees an RCU grace period between the .pre_exit and .exit callbacks, so the .exit
In the Linux kernel, the following vulnerability has been resolved: o ...
In the Linux kernel, the following vulnerability has been resolved: openvswitch: Fix CT limit teardown use-after-free Packet processing uses CT limit state under RCU, while netns teardown frees that state under ovs_mutex. The CT limit pointer was neither removed from readers nor protected by a grace period, allowing packet processing to dereference the freed state. An unprivileged user can trigger this bug from a user and network namespace, causing a slab-use-after-free in ovs_ct_execute() when the netns is torn down. Publish the CT limit pointer through RCU, remove it before teardown, and wait for readers before freeing its contents. Keep ovs_mutex around individual CT limit updates, and use the RCU read-side lock while GET traverses the RCU-protected limit lists. Netns teardown detaches the RCU-protected CT limit state in the pernet .pre_exit callback while holding ovs_mutex. The pernet core guarantees an RCU grace period between the .pre_exit and .exit callbacks, so the .ex...
EPSS
4.7 Medium
CVSS3