CVE-2023-53398 mlx5: fix possible ptp queue fifo use-after-free

What is CVE-2023-53398?

CVE-2023-53398 is a high-severity use after free vulnerability in Linux kernel, published on 18 Sep 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 possible ptp queue fifo use-after-free

Fifo indexes are not checked during pop operations and it leads to potential use-after-free when poping from empty queue. Such case was possible during re-sync action. WARN_ON_ONCE covers future cases.

There were out-of-order cqe spotted which lead to drain of the queue and use-after-free because of lack of fifo pointers check. Special check and counter are added to avoid resync operation if SKB could not exist in the fifo because of OOO cqe (skb_id must be between consumer and producer index).

Weakness: CWE-416

Which versions are affected by CVE-2023-53398?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-53398?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2023-53398 being exploited?

There is no known exploitation of CVE-2023-53398 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2023-53398, DEBIAN-CVE-2023-53398, GHSA-89x9-fp8h-wm3w, UBUNTU-CVE-2023-53398.