# CVE-2023-53393: RDMA/mlx5: Fix mlx5_ib_get_hw_stats when used for device

> A null pointer dereference in the Linux kernel RDMA mlx5 driver causes a system crash when retrieving hardware stats for a device.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** Yes
- **Published:** 18 Sep 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53393, DEBIAN-CVE-2023-53393, GHSA-2633-6xpw-2gqx, ROOT-OS-DEBIAN-11-CVE-2023-53393, UBUNTU-CVE-2023-53393

## What is CVE-2023-53393?

CVE-2023-53393 is a medium-severity 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:

RDMA/mlx5: Fix mlx5_ib_get_hw_stats when used for device

Currently, when mlx5_ib_get_hw_stats() is used for device (port_num = 0),
there is a special handling in order to use the correct counters, but,
port_num is being passed down the stack without any change.  Also, some
functions assume that port_num >=1. As a result, the following oops can
occur.

 BUG: unable to handle page fault for address: ffff89510294f1a8
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 0 P4D 0
 Oops: 0002 [#1] SMP
 CPU: 8 PID: 1382 Comm: devlink Tainted: G W          6.1.0-rc4_for_upstream_base_2022_11_10_16_12 #1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 RIP: 0010:_raw_spin_lock+0xc/0x20
 Call Trace:
  <TASK>
  mlx5_ib_get_native_port_mdev+0x73/0xe0 [mlx5_ib]
  do_get_hw_stats.constprop.0+0x109/0x160 [mlx5_ib]
  mlx5_ib_get_hw_stats+0xad/0x180 [mlx5_ib]
  ib_setup_device_attrs+0xf0/0x290 [ib_core]
  ib_register_device+0x3bb/0x510 [ib_core]
  ? atomic_notifier_chain_register+0x67/0x80
  __mlx5_ib_add+0x2b/0x80 [mlx5_ib]
  mlx5r_probe+0xb8/0x150 [mlx5_ib]
  ? auxiliary_match_id+0x6a/0x90
  auxiliary_bus_probe+0x3c/0x70
  ? driver_sysfs_add+0x6b/0x90
  really_probe+0xcd/0x380
  __driver_probe_device+0x80/0x170
  driver_probe_device+0x1e/0x90
  __device_attach_driver+0x7d/0x100
  ? driver_allows_async_probing+0x60/0x60
  ? driver_allows_async_probing+0x60/0x60
  bus_for_each_drv+0x7b/0xc0
  __device_attach+0xbc/0x200
  bus_probe_device+0x87/0xa0
  device_add+0x404/0x940
  ? dev_set_name+0x53/0x70
  __auxiliary_device_add+0x43/0x60
  add_adev+0x99/0xe0 [mlx5_core]
  mlx5_attach_device+0xc8/0x120 [mlx5_core]
  mlx5_load_one_devl_locked+0xb2/0xe0 [mlx5_core]
  devlink_reload+0x133/0x250
  devlink_nl_cmd_reload+0x480/0x570
  ? devlink_nl_pre_doit+0x44/0x2b0
  genl_family_rcv_msg_doit.isra.0+0xc2/0x110
  genl_rcv_msg+0x180/0x2b0
  ? devlink_nl_cmd_region_read_dumpit+0x540/0x540
  ? devlink_reload+0x250/0x250
  ? devlink_put+0x50/0x50
  ? genl_family_rcv_msg_doit.isra.0+0x110/0x110
  netlink_rcv_skb+0x54/0x100
  genl_rcv+0x24/0x40
  netlink_unicast+0x1f6/0x2c0
  netlink_sendmsg+0x237/0x490
  sock_sendmsg+0x33/0x40
  __sys_sendto+0x103/0x160
  ? handle_mm_fault+0x10e/0x290
  ? do_user_addr_fault+0x1c0/0x5f0
  __x64_sys_sendto+0x25/0x30
  do_syscall_64+0x3d/0x90
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fix it by setting port_num to 1 in order to get device status and remove
unused variable.

## Which versions are affected by CVE-2023-53393?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53393?

Apply the vendor's patch.

## Is CVE-2023-53393 being exploited?

There is no known exploitation of CVE-2023-53393 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53393 and fix it if it is affected.

What it is: CVE-2023-53393 is a medium-severity 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.
Exploitation: There is no known exploitation of CVE-2023-53393 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2023-53393/ (Markdown: https://insights.sbomify.com/CVE-2023-53393/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53393
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53393
- OSV: https://osv.dev/vulnerability/CVE-2023-53393

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53393/
Summaries are generated and may contain mistakes; the official description above is the record.
