CVE-2025-68232

A flaw was found in the Linux kernel's virtual Ethernet device (veth) component. A race condition within the veth_xmit() function, caused by an incorrect use of an internal API, can lead to the transmit queue (TXQ) becoming permanently stalled. This issue can result in a Denial of Service (DoS) where network traffic halts on affected systems.

A denial of service flaw of moderate impact was found in the Linux kernel's virtual Ethernet (veth) driver. A race condition in the veth_xmit() function, caused by an incorrect producer-side use of the __ptr_ring_empty() API, can result in a "lost wakeup" in which the transmit queue remains permanently stopped and network traffic through the veth device halts. Triggering the race requires an actor with local access able to generate traffic through an affected veth pair (veth devices are commonly used for container and virtual machine networking), and the impact is limited to availability, with no effect on confidentiality or integrity. Red Hat assessed this flaw as Moderate severity with a CVSS 3.1 score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), lower than the upstream CVE.org score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), because triggering the issue requires local access and traffic through a veth device rather than an unauthenticated remote vector. The vulnerable code, introduced upstream by commit dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to reduce TX drops"), is not present in the Red Hat Enterprise Linux 7, 8, 9, and 10 kernel and kernel-rt update streams or in Red Hat In-Vehicle OS 1.1, so those products are not affected; the remaining Red Hat Enterprise Linux 6 ELS relationship is out of support scope.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.