Описание
In the Linux kernel, the following vulnerability has been resolved:
vsock: Update rx_bytes on read_skb()
Make sure virtio_transport_inc_rx_pkt() and virtio_transport_dec_rx_pkt()
calls are balanced (i.e. virtio_vsock_sock::rx_bytes doesn't lie) after
vsock_transport::read_skb().
While here, also inform the peer that we've freed up space and it has more
credit.
Failing to update rx_bytes after packet is dequeued leads to a warning on
SOCK_STREAM recv():
[ 233.396654] rx_queue is empty, but rx_bytes is non-zero
[ 233.396702] WARNING: CPU: 11 PID: 40601 at net/vmw_vsock/virtio_transport_common.c:589
A flaw was found in the Linux kernel's vsock component. A local attacker can exploit an imbalance in the rx_bytes tracking mechanism, specifically after vsock_transport::read_skb() fails to update the received bytes count when a packet is dequeued. This can lead to a warning message indicating an empty receive queue with non-zero rx_bytes, potentially resulting in a denial of service (DoS) for the system.
Меры по смягчению последствий
To mitigate this issue, prevent the vsock kernel module from loading if it is not required. This can be achieved by blacklisting the module.
- Create a new file
/etc/modprobe.d/blacklist-vsock.confwith the following content:
- Regenerate the initramfs to ensure the blacklist is applied during boot: For RHEL 8 and 9:
For RHEL 7:
- Reboot the system for the changes to take effect.
Warning: Blacklisting the
vsockmodule will disable inter-VM communication usingvsockand may impact functionality that relies on it. A system reboot is required for the mitigation to be fully applied.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 | 13.05.2025 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 | 13.05.2025 |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: vsock: Update rx_bytes on read_skb() Make sure virtio_transport_inc_rx_pkt() and virtio_transport_dec_rx_pkt() calls are balanced (i.e. virtio_vsock_sock::rx_bytes doesn't lie) after vsock_transport::read_skb(). While here, also inform the peer that we've freed up space and it has more credit. Failing to update rx_bytes after packet is dequeued leads to a warning on SOCK_STREAM recv(): [ 233.396654] rx_queue is empty, but rx_bytes is non-zero [ 233.396702] WARNING: CPU: 11 PID: 40601 at net/vmw_vsock/virtio_transport_common.c:589
In the Linux kernel, the following vulnerability has been resolved: vsock: Update rx_bytes on read_skb() Make sure virtio_transport_inc_rx_pkt() and virtio_transport_dec_rx_pkt() calls are balanced (i.e. virtio_vsock_sock::rx_bytes doesn't lie) after vsock_transport::read_skb(). While here, also inform the peer that we've freed up space and it has more credit. Failing to update rx_bytes after packet is dequeued leads to a warning on SOCK_STREAM recv(): [ 233.396654] rx_queue is empty, but rx_bytes is non-zero [ 233.396702] WARNING: CPU: 11 PID: 40601 at net/vmw_vsock/virtio_transport_common.c:589
In the Linux kernel, the following vulnerability has been resolved: v ...
In the Linux kernel, the following vulnerability has been resolved: vsock: Update rx_bytes on read_skb() Make sure virtio_transport_inc_rx_pkt() and virtio_transport_dec_rx_pkt() calls are balanced (i.e. virtio_vsock_sock::rx_bytes doesn't lie) after vsock_transport::read_skb(). While here, also inform the peer that we've freed up space and it has more credit. Failing to update rx_bytes after packet is dequeued leads to a warning on SOCK_STREAM recv(): [ 233.396654] rx_queue is empty, but rx_bytes is non-zero [ 233.396702] WARNING: CPU: 11 PID: 40601 at net/vmw_vsock/virtio_transport_common.c:589
EPSS
5.5 Medium
CVSS3