# CVE-2025-38402: idpf: return 0 size for RSS key if not supported

> A local attacker can cause a kernel crash by triggering an invalid memory allocation in the idpf driver when RSS is unsupported.

- **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:** 25 Jul 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-38402, DEBIAN-CVE-2025-38402, GHSA-xq77-3x66-fcxc, ROOT-OS-UBUNTU-2404-CVE-2025-38402, UBUNTU-CVE-2025-38402

## What is CVE-2025-38402?

CVE-2025-38402 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 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:

idpf: return 0 size for RSS key if not supported

Returning -EOPNOTSUPP from function returning u32 is leading to
cast and invalid size value as a result.

-EOPNOTSUPP as a size probably will lead to allocation fail.

Command: ethtool -x eth0
It is visible on all devices that don't have RSS caps set.

[  136.615917] Call Trace:
[  136.615921]  <TASK>
[  136.615927]  ? __warn+0x89/0x130
[  136.615942]  ? __alloc_frozen_pages_noprof+0x322/0x330
[  136.615953]  ? report_bug+0x164/0x190
[  136.615968]  ? handle_bug+0x58/0x90
[  136.615979]  ? exc_invalid_op+0x17/0x70
[  136.615987]  ? asm_exc_invalid_op+0x1a/0x20
[  136.616001]  ? rss_prepare_get.constprop.0+0xb9/0x170
[  136.616016]  ? __alloc_frozen_pages_noprof+0x322/0x330
[  136.616028]  __alloc_pages_noprof+0xe/0x20
[  136.616038]  ___kmalloc_large_node+0x80/0x110
[  136.616072]  __kmalloc_large_node_noprof+0x1d/0xa0
[  136.616081]  __kmalloc_noprof+0x32c/0x4c0
[  136.616098]  ? rss_prepare_get.constprop.0+0xb9/0x170
[  136.616105]  rss_prepare_get.constprop.0+0xb9/0x170
[  136.616114]  ethnl_default_doit+0x107/0x3d0
[  136.616131]  genl_family_rcv_msg_doit+0x100/0x160
[  136.616147]  genl_rcv_msg+0x1b8/0x2c0
[  136.616156]  ? __pfx_ethnl_default_doit+0x10/0x10
[  136.616168]  ? __pfx_genl_rcv_msg+0x10/0x10
[  136.616176]  netlink_rcv_skb+0x58/0x110
[  136.616186]  genl_rcv+0x28/0x40
[  136.616195]  netlink_unicast+0x19b/0x290
[  136.616206]  netlink_sendmsg+0x222/0x490
[  136.616215]  __sys_sendto+0x1fd/0x210
[  136.616233]  __x64_sys_sendto+0x24/0x30
[  136.616242]  do_syscall_64+0x82/0x160
[  136.616252]  ? __sys_recvmsg+0x83/0xe0
[  136.616265]  ? syscall_exit_to_user_mode+0x10/0x210
[  136.616275]  ? do_syscall_64+0x8e/0x160
[  136.616282]  ? __count_memcg_events+0xa1/0x130
[  136.616295]  ? count_memcg_events.constprop.0+0x1a/0x30
[  136.616306]  ? handle_mm_fault+0xae/0x2d0
[  136.616319]  ? do_user_addr_fault+0x379/0x670
[  136.616328]  ? clear_bhb_loop+0x45/0xa0
[  136.616340]  ? clear_bhb_loop+0x45/0xa0
[  136.616349]  ? clear_bhb_loop+0x45/0xa0
[  136.616359]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  136.616369] RIP: 0033:0x7fd30ba7b047
[  136.616376] Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d bd d5 0c 00 00 41 89 ca 74 10 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 71 c3 55 48 83 ec 30 44 89 4c 24 2c 4c 89 44
[  136.616381] RSP: 002b:00007ffde1796d68 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
[  136.616388] RAX: ffffffffffffffda RBX: 000055d7bd89f2a0 RCX: 00007fd30ba7b047
[  136.616392] RDX: 0000000000000028 RSI: 000055d7bd89f3b0 RDI: 0000000000000003
[  136.616396] RBP: 00007ffde1796e10 R08: 00007fd30bb4e200 R09: 000000000000000c
[  136.616399] R10: 0000000000000000 R11: 0000000000000202 R12: 000055d7bd89f340
[  136.616403] R13: 000055d7bd89f3b0 R14: 000055d78943f200 R15: 0000000000000000

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-38402?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-38402?

Apply the vendor's patch.

## Is CVE-2025-38402 being exploited?

There is no known exploitation of CVE-2025-38402 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-2025-38402 and fix it if it is affected.

What it is: CVE-2025-38402 is a medium-severity vulnerability in Linux kernel, published on 25 Jul 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-2025-38402 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-2025-38402/ (Markdown: https://insights.sbomify.com/CVE-2025-38402/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38402
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38402
- OSV: https://osv.dev/vulnerability/CVE-2025-38402

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38402/
Summaries are generated and may contain mistakes; the official description above is the record.
