CVE-2023-54238 mlx5: fix skb leak while fifo resync and push
A memory leak in the mlx5 network driver can lead to resource exhaustion and denial of service during PTP resync operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54238?
CVE-2023-54238 is a high-severity denial of service vulnerability in Linux, published on 30 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
mlx5: fix skb leak while fifo resync and push
During ptp resync operation SKBs were poped from the fifo but were never freed neither by napi_consume nor by dev_kfree_skb_any. Add call to napi_consume_skb to properly free SKBs.
Another leak was happening because mlx5e_skb_fifo_has_room() had an error in the check. Comparing free running counters works well unless C promotes the types to something wider than the counter. In this case counters are u16 but the result of the substraction is promouted to int and it causes wrong result (negative value) of the check when producer have already overlapped but consumer haven't yet. Explicit cast to u16 fixes the issue.
Which versions are affected by CVE-2023-54238?
How do I fix CVE-2023-54238?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-54238 being exploited?
There is no known exploitation of CVE-2023-54238 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54238, DEBIAN-CVE-2023-54238, GHSA-48xp-xhc9-g2gm, UBUNTU-CVE-2023-54238.