CVE-2025-68232VulnerabilityPublished 16 Dec 2025Updated 31 Jul 2026

CVE-2025-68232: Linux hwe edge · In the Linux kernel, the following vulnerability has been resolved: veth: more robust handing of race to avoid txq getting stuck Commit dc82a33297fc

Affects linux-hwe-edgeSource GCVE Database

Not known to be exploited · CVSS 7.5 Medium · fixed in 6.17.0-1018.18 : update linux-hwe-edge when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.17.0-1018.18, 6.17.0-1010.10~24.04.1, 6.17.0-1009.9~24.04.3 +2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-mrvq-mp59-qvj4

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
linux-hwe-edge	Affected <6.17.0-1009.9~24.04.2 <6.17.0-1010.10~24.04.1 <6.17.0-1009.9~24.04.3 <6.17.0-19.19~24.04.2 <6.17.0-1018.18	Fixed in 6.17.0-1009.9~24.04.2 6.17.0-1010.10~24.04.1 6.17.0-1009.9~24.04.3 6.17.0-19.19~24.04.2 6.17.0-1018.18

AI-suggested

A fix has been implemented in the Linux kernel to address this race condition by changing the queue wake-up logic. Users should apply the official kernel patch containing commit dc82a33297fc or later versions that include this fix. Since this is a kernel-level issue, upgrading to a patched kernel release is the recommended remediation. Patch status is not explicitly confirmed here; check the vendor or Linux kernel advisories for the exact fixed kernel versions and apply updates accordingly.

Description

In the Linux kernel, the following vulnerability has been resolved: veth: more robust handing of race to avoid txq getting stuck Commit dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to reduce TX drops") introduced a race condition that can lead to a permanently stalled TXQ. This was observed in production on ARM64 systems (Ampere Altra Max). The race occurs in veth_xmit(). The producer observes a full ptr_ring and stops the queue (netif_tx_stop_queue()). The subsequent conditional logic, intended to re-wake the queue if the consumer had just emptied it (if (__ptr_ring_empty(...)) netif_tx_wake_queue()), can fail. This leads to a "lost wakeup" where the TXQ remains stopped (QUEUE_STATE_DRV_XOFF) and traffic halts. This failure is caused by an incorrect use of the __ptr_ring_empty() API from the producer side. As noted in kernel comments, this check is not guaranteed to be correct if a consumer is operating on another CPU. The empty test is based on ptr_ring->consumer_head, making it reliable only for the consumer. Using this check from the producer side is fundamentally racy. This patch fixes the race by adopting the more robust logic from an earlier version V4 of the patchset, which always flushed the peer: (1) In veth_xmit(), the racy conditional wake-up logic and its memory barrier are removed. Instead, after stopping the queue, we unconditionally call __veth_xdp_flush(rq). This guarantees that the NAPI consumer is scheduled, making it solely responsible for re-waking the TXQ. This handles the race where veth_poll() consumes all packets and completes NAPI *before* veth_xmit() on the producer side has called netif_tx_stop_queue. The __veth_xdp_flush(rq) will observe rx_notify_masked is false and schedule NAPI. (2) On the consumer side, the logic for waking the peer TXQ is moved out of veth_xdp_rcv() and placed at the end of the veth_poll() function. This placement is part of fixing the race, as the netif_tx_queue_stopped() check must occur after rx_notify_masked is potentially set to false during NAPI completion. This handles the race where veth_poll() consumes all packets, but haven't finished (rx_notify_masked is still true). The producer veth_xmit() stops the TXQ and __veth_xdp_flush(rq) will observe rx_notify_masked is true, meaning not starting NAPI. Then veth_poll() change rx_notify_masked to false and stops NAPI. Before exiting veth_poll() will observe TXQ is stopped and wake it up.

Impact

The vulnerability causes a denial of service condition by permanently stalling the transmit queue in the veth network driver, leading to halted network traffic on affected systems. There is no impact on confidentiality or integrity. This affects network availability, particularly observed on ARM64 platforms such as Ampere Altra Max.

Summary

CVE-2025-68232 describes a race condition in the Linux kernel veth driver introduced by commit dc82a33297fc. The producer side incorrectly uses __ptr_ring_empty() to decide whether to wake the transmit queue, which is unreliable due to concurrent consumer operations on another CPU. This can cause the TXQ to remain stopped indefinitely (QUEUE_STATE_DRV_XOFF), resulting in halted network traffic. The fix removes the racy conditional wake-up logic and instead unconditionally flushes the peer queue to ensure the consumer schedules NAPI and is responsible for waking the TXQ. Additionally, the wake-up logic is moved to the end of the consumer's veth_poll() function to handle races properly.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Jul 2026, 18:28 UTC

Technical details

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