# CVE-2025-21717: net/mlx5e: add missing cpu_to_node to kvzalloc_node in mlx5e_open_xdpredirect_sq

> A missing CPU-to-node conversion in the mlx5e driver causes an out-of-bounds access and kernel panic when opening network interfaces on high-CPU systems.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 27 Feb 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-21717, GHSA-6v7v-ggwx-mwx7, UBUNTU-CVE-2025-21717

## What is CVE-2025-21717?

CVE-2025-21717 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 Feb 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: add missing cpu_to_node to kvzalloc_node in mlx5e_open_xdpredirect_sq

kvzalloc_node is not doing a runtime check on the node argument
(__alloc_pages_node_noprof does have a VM_BUG_ON, but it expands to
nothing on !CONFIG_DEBUG_VM builds), so doing any ethtool/netlink
operation that calls mlx5e_open on a CPU that's larger that MAX_NUMNODES
triggers OOB access and panic (see the trace below).

Add missing cpu_to_node call to convert cpu id to node id.

[  165.427394] mlx5_core 0000:5c:00.0 beth1: Link up
[  166.479327] BUG: unable to handle page fault for address: 0000000800000010
[  166.494592] #PF: supervisor read access in kernel mode
[  166.505995] #PF: error_code(0x0000) - not-present page
...
[  166.816958] Call Trace:
[  166.822380]  <TASK>
[  166.827034]  ? __die_body+0x64/0xb0
[  166.834774]  ? page_fault_oops+0x2cd/0x3f0
[  166.843862]  ? exc_page_fault+0x63/0x130
[  166.852564]  ? asm_exc_page_fault+0x22/0x30
[  166.861843]  ? __kvmalloc_node_noprof+0x43/0xd0
[  166.871897]  ? get_partial_node+0x1c/0x320
[  166.880983]  ? deactivate_slab+0x269/0x2b0
[  166.890069]  ___slab_alloc+0x521/0xa90
[  166.898389]  ? __kvmalloc_node_noprof+0x43/0xd0
[  166.908442]  __kmalloc_node_noprof+0x216/0x3f0
[  166.918302]  ? __kvmalloc_node_noprof+0x43/0xd0
[  166.928354]  __kvmalloc_node_noprof+0x43/0xd0
[  166.938021]  mlx5e_open_channels+0x5e2/0xc00
[  166.947496]  mlx5e_open_locked+0x3e/0xf0
[  166.956201]  mlx5e_open+0x23/0x50
[  166.963551]  __dev_open+0x114/0x1c0
[  166.971292]  __dev_change_flags+0xa2/0x1b0
[  166.980378]  dev_change_flags+0x21/0x60
[  166.988887]  do_setlink+0x38d/0xf20
[  166.996628]  ? ep_poll_callback+0x1b9/0x240
[  167.005910]  ? __nla_validate_parse.llvm.10713395753544950386+0x80/0xd70
[  167.020782]  ? __wake_up_sync_key+0x52/0x80
[  167.030066]  ? __mutex_lock+0xff/0x550
[  167.038382]  ? security_capable+0x50/0x90
[  167.047279]  rtnl_setlink+0x1c9/0x210
[  167.055403]  ? ep_poll_callback+0x1b9/0x240
[  167.064684]  ? security_capable+0x50/0x90
[  167.073579]  rtnetlink_rcv_msg+0x2f9/0x310
[  167.082667]  ? rtnetlink_bind+0x30/0x30
[  167.091173]  netlink_rcv_skb+0xb1/0xe0
[  167.099492]  netlink_unicast+0x20f/0x2e0
[  167.108191]  netlink_sendmsg+0x389/0x420
[  167.116896]  __sys_sendto+0x158/0x1c0
[  167.125024]  __x64_sys_sendto+0x22/0x30
[  167.133534]  do_syscall_64+0x63/0x130
[  167.141657]  ? __irq_exit_rcu.llvm.17843942359718260576+0x52/0xd0
[  167.155181]  entry_SYSCALL_64_after_hwframe+0x4b/0x53

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2025-21717?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-21717?

Apply the vendor's patch.

## Is CVE-2025-21717 being exploited?

There is no known exploitation of CVE-2025-21717 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-2025-21717 and fix it if it is affected.

What it is: CVE-2025-21717 is a high-severity memory corruption vulnerability in Linux kernel, published on 27 Feb 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-2025-21717 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-2025-21717/ (Markdown: https://insights.sbomify.com/CVE-2025-21717/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21717
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21717
- OSV: https://osv.dev/vulnerability/CVE-2025-21717

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21717/
Summaries are generated and may contain mistakes; the official description above is the record.
