Описание
In the Linux kernel, the following vulnerability has been resolved:
ovpn: replace bind when clearing stale local source
The UDP output fallback clears bind->local in place when the remembered
source address is no longer usable. The bind is RCU-published and read
locklessly by concurrent TX, so an IPv6 reader can observe a torn
address.
Retry the route lookup with source address autoselection without
modifying the bind. After a successful lookup, revalidate the bind and
route key under peer->lock, reset the dst cache, and best-effort publish
a replacement bind with a wildcard local address.
Do not cache the resolved dst when clearing the local source. Replacing
the source invalidates all per-CPU cache entries, while
dst_cache_set_ip4 and dst_cache_set_ip6 update only the current CPU
slot. The current packet can still use the resolved route; if bind
allocation fails, a later cache miss retries the repair.
A flaw was found in the Linux kernel's OpenVPN (ovpn) module. A local user can cause a Denial of Service (DoS) or network disruption during concurrent network traffic when an outdated local source address is cleared. Because the address is modified in place without proper synchronization, concurrent transmission operations may read a torn, partially updated address, leading to incorrect routing and packet transmission failures.
Отчет
An RCU published ovpn bind can be modified in place while concurrent TX paths read it without locking. When a remembered IPv6 source address becomes unusable, clearing the 128 bit local address can be observed as a torn value and may cause route lookup or cached routing state to use an inconsistent source address. The most credible effects are packet loss, incorrect source address selection, disruption of an OVPN peer, or limited interaction with source based routing policy. No UAF, OOB access, arbitrary write, or direct kernel crash primitive is established by the shown code. For the CVSS the PR:L value in the paranoid score represents deployments where a container or restricted network service has delegated control over its OVPN interface or network namespace. The race requires the remembered local source to become invalid while concurrent transmission is active, so AC:H is appropriate. A remote peer can contribute traffic but cannot reliably trigger the required local address invalidation through network traffic alone. Impact is primarily availability related, with limited confidentiality or integrity impact remaining possible if an inconsistent source selects an unintended routing path.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred |
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Дополнительная информация
Статус:
EPSS
2.5 Low
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: ovpn: replace bind when clearing stale local source The UDP output fallback clears bind->local in place when the remembered source address is no longer usable. The bind is RCU-published and read locklessly by concurrent TX, so an IPv6 reader can observe a torn address. Retry the route lookup with source address autoselection without modifying the bind. After a successful lookup, revalidate the bind and route key under peer->lock, reset the dst cache, and best-effort publish a replacement bind with a wildcard local address. Do not cache the resolved dst when clearing the local source. Replacing the source invalidates all per-CPU cache entries, while dst_cache_set_ip4 and dst_cache_set_ip6 update only the current CPU slot. The current packet can still use the resolved route; if bind allocation fails, a later cache miss retries the repair.
In the Linux kernel, the following vulnerability has been resolved: ovpn: replace bind when clearing stale local source The UDP output fallback clears bind->local in place when the remembered source address is no longer usable. The bind is RCU-published and read locklessly by concurrent TX, so an IPv6 reader can observe a torn address. Retry the route lookup with source address autoselection without modifying the bind. After a successful lookup, revalidate the bind and route key under peer->lock, reset the dst cache, and best-effort publish a replacement bind with a wildcard local address. Do not cache the resolved dst when clearing the local source. Replacing the source invalidates all per-CPU cache entries, while dst_cache_set_ip4 and dst_cache_set_ip6 update only the current CPU slot. The current packet can still use the resolved route; if bind allocation fails, a later cache miss retries the repair.
In the Linux kernel, the following vulnerability has been resolved: o ...
In the Linux kernel, the following vulnerability has been resolved: ovpn: replace bind when clearing stale local source The UDP output fallback clears bind->local in place when the remembered source address is no longer usable. The bind is RCU-published and read locklessly by concurrent TX, so an IPv6 reader can observe a torn address. Retry the route lookup with source address autoselection without modifying the bind. After a successful lookup, revalidate the bind and route key under peer->lock, reset the dst cache, and best-effort publish a replacement bind with a wildcard local address. Do not cache the resolved dst when clearing the local source. Replacing the source invalidates all per-CPU cache entries, while dst_cache_set_ip4 and dst_cache_set_ip6 update only the current CPU slot. The current packet can still use the resolved route; if bind allocation fails, a later cache miss retries the repair.
EPSS
2.5 Low
CVSS3