---
id: CVE-2026-31515
title: 'af_key: validate families in pfkey_send_migrate()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  af_key: validate families in pfkey_send_migrate()

  syzbot was able to trigger a crash in skb_put() [1]

  Issue is that pfkey_send_migrate() does not check old/new famili…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    d0c5aa8dd38887714f1aad04236a3620b56a5e4e
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    e06b596fc4eb01936a2e5dccad17c946d660bab8
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    8ddf8de7e758f6888988467af9ffc8adf589fb16
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    d3225e6b9bd51ec177970a628fe4b11237ce87d5
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    7b18692c59afb8e5c364c8e3ac01e51dd6b52028
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    83f644ea92987c100b82d8481ae2230faeed3d34
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    ee836e820a40e2ca4da8af7310bff92d586772d4
  - >-
    Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece <
    eb2d16a7d599dc9d4df391b5e660df9949963786
  - Linux 2.6.21
published: '2026-04-22'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:47:35.688Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31515'
references:
  - url: 'https://git.kernel.org/stable/c/d0c5aa8dd38887714f1aad04236a3620b56a5e4e'
  - url: 'https://git.kernel.org/stable/c/e06b596fc4eb01936a2e5dccad17c946d660bab8'
  - url: 'https://git.kernel.org/stable/c/8ddf8de7e758f6888988467af9ffc8adf589fb16'
  - url: 'https://git.kernel.org/stable/c/d3225e6b9bd51ec177970a628fe4b11237ce87d5'
  - url: 'https://git.kernel.org/stable/c/7b18692c59afb8e5c364c8e3ac01e51dd6b52028'
  - url: 'https://git.kernel.org/stable/c/83f644ea92987c100b82d8481ae2230faeed3d34'
  - url: 'https://git.kernel.org/stable/c/ee836e820a40e2ca4da8af7310bff92d586772d4'
  - url: 'https://git.kernel.org/stable/c/eb2d16a7d599dc9d4df391b5e660df9949963786'
tags:
  - cve.org
epss: 0.00171
epssPercentile: 0.05675
ingestedAt: '2026-09-08T15:33:26.990Z'
---

## Overview

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

af_key: validate families in pfkey_send_migrate()

syzbot was able to trigger a crash in skb_put() [1]

Issue is that pfkey_send_migrate() does not check old/new families,
and that set_ipsecrequest() @family argument was truncated,
thus possibly overfilling the skb.

Validate families early, do not wait set_ipsecrequest().

[1]

skbuff: skb_over_panic: text:ffffffff8a752120 len:392 put:16 head:ffff88802a4ad040 data:ffff88802a4ad040 tail:0x188 end:0x180 dev:<NULL>
 kernel BUG at net/core/skbuff.c:214 !
Call Trace:
 <TASK>
  skb_over_panic net/core/skbuff.c:219 [inline]
  skb_put+0x159/0x210 net/core/skbuff.c:2655
  skb_put_zero include/linux/skbuff.h:2788 [inline]
  set_ipsecrequest net/key/af_key.c:3532 [inline]
  pfkey_send_migrate+0x1270/0x2e50 net/key/af_key.c:3636
  km_migrate+0x155/0x260 net/xfrm/xfrm_state.c:2848
  xfrm_migrate+0x2140/0x2450 net/xfrm/xfrm_policy.c:4705
  xfrm_do_migrate+0x8ff/0xaa0 net/xfrm/xfrm_user.c:3150

## Affected

- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < d0c5aa8dd38887714f1aad04236a3620b56a5e4e`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < e06b596fc4eb01936a2e5dccad17c946d660bab8`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < 8ddf8de7e758f6888988467af9ffc8adf589fb16`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < d3225e6b9bd51ec177970a628fe4b11237ce87d5`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < 7b18692c59afb8e5c364c8e3ac01e51dd6b52028`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < 83f644ea92987c100b82d8481ae2230faeed3d34`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < ee836e820a40e2ca4da8af7310bff92d586772d4`
- `Linux >= 08de61beab8a21c8e0b3906a97defda5f1f66ece < eb2d16a7d599dc9d4df391b5e660df9949963786`
- `Linux 2.6.21`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.