# CVE-2023-53999: net/mlx5e: TC, Fix internal port memory leak

> A memory leak in the Linux kernel mlx5e driver allows local attackers with high privileges to cause denial of service by exhausting kernel memory.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Dec 2025
- **Updated:** 3 Oct 2026
- **Also known as:** BELL-CVE-2023-53999, DEBIAN-CVE-2023-53999, GHSA-x7x5-xvrp-r655, ROOT-OS-DEBIAN-12-CVE-2023-53999, UBUNTU-CVE-2023-53999

## What is CVE-2023-53999?

CVE-2023-53999 is a memory corruption vulnerability in Linux, published on 24 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:

net/mlx5e: TC, Fix internal port memory leak

The flow rule can be splited, and the extra post_act rules are added
to post_act table. It's possible to trigger memleak when the rule
forwards packets from internal port and over tunnel, in the case that,
for example, CT 'new' state offload is allowed. As int_port object is
assigned to the flow attribute of post_act rule, and its refcnt is
incremented by mlx5e_tc_int_port_get(), but mlx5e_tc_int_port_put() is
not called, the refcnt is never decremented, then int_port is never
freed.

The kmemleak reports the following error:
unreferenced object 0xffff888128204b80 (size 64):
  comm "handler20", pid 50121, jiffies 4296973009 (age 642.932s)
  hex dump (first 32 bytes):
    01 00 00 00 19 00 00 00 03 f0 00 00 04 00 00 00  ................
    98 77 67 41 81 88 ff ff 98 77 67 41 81 88 ff ff  .wgA.....wgA....
  backtrace:
    [<00000000e992680d>] kmalloc_trace+0x27/0x120
    [<000000009e945a98>] mlx5e_tc_int_port_get+0x3f3/0xe20 [mlx5_core]
    [<0000000035a537f0>] mlx5e_tc_add_fdb_flow+0x473/0xcf0 [mlx5_core]
    [<0000000070c2cec6>] __mlx5e_add_fdb_flow+0x7cf/0xe90 [mlx5_core]
    [<000000005cc84048>] mlx5e_configure_flower+0xd40/0x4c40 [mlx5_core]
    [<000000004f8a2031>] mlx5e_rep_indr_offload.isra.0+0x10e/0x1c0 [mlx5_core]
    [<000000007df797dc>] mlx5e_rep_indr_setup_tc_cb+0x90/0x130 [mlx5_core]
    [<0000000016c15cc3>] tc_setup_cb_add+0x1cf/0x410
    [<00000000a63305b4>] fl_hw_replace_filter+0x38f/0x670 [cls_flower]
    [<000000008bc9e77c>] fl_change+0x1fd5/0x4430 [cls_flower]
    [<00000000e7f766e4>] tc_new_tfilter+0x867/0x2010
    [<00000000e101c0ef>] rtnetlink_rcv_msg+0x6fc/0x9f0
    [<00000000e1111d44>] netlink_rcv_skb+0x12c/0x360
    [<0000000082dd6c8b>] netlink_unicast+0x438/0x710
    [<00000000fc568f70>] netlink_sendmsg+0x794/0xc50
    [<0000000016e92590>] sock_sendmsg+0xc5/0x190

So fix this by moving int_port cleanup code to the flow attribute
free helper, which is used by all the attribute free cases.

## Which versions are affected by CVE-2023-53999?


## How do I fix CVE-2023-53999?

Apply the vendor's patch.

## Is CVE-2023-53999 being exploited?

There is no known exploitation of CVE-2023-53999 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53999 and fix it if it is affected.

What it is: CVE-2023-53999 is a memory corruption vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-53999 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-53999/ (Markdown: https://insights.sbomify.com/CVE-2023-53999/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53999
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53999
- OSV: https://osv.dev/vulnerability/CVE-2023-53999

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53999/
Summaries are generated and may contain mistakes; the official description above is the record.