# CVE-2025-38439: bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT

> A bug in the bnxt_en driver causes incorrect DMA unmap lengths during XDP redirects, triggering kernel warnings and potential instability on systems with IOMMU enabled.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-65705, AZL-72917, BELL-CVE-2025-38439, DEBIAN-CVE-2025-38439, GHSA-55p2-7r59-rr9c, ROOT-OS-DEBIAN-11-CVE-2025-38439, ROOT-OS-DEBIAN-12-CVE-2025-38439, ROOT-OS-UBUNTU-2204-CVE-2025-38439, ROOT-OS-UBUNTU-2404-CVE-2025-38439, UBUNTU-CVE-2025-38439

## What is CVE-2025-38439?

CVE-2025-38439 is a critical vulnerability in Debian Debian Linux, published on 25 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT

When transmitting an XDP_REDIRECT packet, call dma_unmap_len_set()
with the proper length instead of 0.  This bug triggers this warning
on a system with IOMMU enabled:

WARNING: CPU: 36 PID: 0 at drivers/iommu/dma-iommu.c:842 __iommu_dma_unmap+0x159/0x170
RIP: 0010:__iommu_dma_unmap+0x159/0x170
Code: a8 00 00 00 00 48 c7 45 b0 00 00 00 00 48 c7 45 c8 00 00 00 00 48 c7 45 a0 ff ff ff ff 4c 89 45
b8 4c 89 45 c0 e9 77 ff ff ff <0f> 0b e9 60 ff ff ff e8 8b bf 6a 00 66 66 2e 0f 1f 84 00 00 00 00
RSP: 0018:ff22d31181150c88 EFLAGS: 00010206
RAX: 0000000000002000 RBX: 00000000e13a0000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ff22d31181150cf0 R08: ff22d31181150ca8 R09: 0000000000000000
R10: 0000000000000000 R11: ff22d311d36c9d80 R12: 0000000000001000
R13: ff13544d10645010 R14: ff22d31181150c90 R15: ff13544d0b2bac00
FS: 0000000000000000(0000) GS:ff13550908a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005be909dacff8 CR3: 0008000173408003 CR4: 0000000000f71ef0
PKRU: 55555554
Call Trace:
<IRQ>
? show_regs+0x6d/0x80
? __warn+0x89/0x160
? __iommu_dma_unmap+0x159/0x170
? report_bug+0x17e/0x1b0
? handle_bug+0x46/0x90
? exc_invalid_op+0x18/0x80
? asm_exc_invalid_op+0x1b/0x20
? __iommu_dma_unmap+0x159/0x170
? __iommu_dma_unmap+0xb3/0x170
iommu_dma_unmap_page+0x4f/0x100
dma_unmap_page_attrs+0x52/0x220
? srso_alias_return_thunk+0x5/0xfbef5
? xdp_return_frame+0x2e/0xd0
bnxt_tx_int_xdp+0xdf/0x440 [bnxt_en]
__bnxt_poll_work_done+0x81/0x1e0 [bnxt_en]
bnxt_poll+0xd3/0x1e0 [bnxt_en]

## Which versions are affected by CVE-2025-38439?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38439?

Apply the vendor's patch.

## Is CVE-2025-38439 being exploited?

There is no known exploitation of CVE-2025-38439 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38439 and fix it if it is affected.

What it is: CVE-2025-38439 is a critical vulnerability in Debian Debian Linux, published on 25 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-38439 in the wild and no public exploit code.

Affected product: Debian Debian 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-2025-38439/ (Markdown: https://insights.sbomify.com/CVE-2025-38439/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38439
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38439
- OSV: https://osv.dev/vulnerability/CVE-2025-38439

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38439/
Summaries are generated and may contain mistakes; the official description above is the record.