---
id: CVE-2026-93105
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  esp: do not unref managed frag pages in esp_ssg_unref()

  esp_ssg_unref() releases the page references held on the source
  scatterlist after the AEAD operation completes.…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  esp: do not unref managed frag pages in esp_ssg_unref()

  esp_ssg_unref() releases the page references held on the source
  scatterlist after the AEAD operation completes.…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <
    26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf
  - >-
    Linux >= cac2661c53f35cbe651bef9b07026a5a05ab8ce0 <
    21697720ff43b8dfa25b8e8d9ca7f56f4597fc80
  - Linux 4.11
published: '2026-09-17'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:18:20.667'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93105'
references:
  - url: 'https://git.kernel.org/stable/c/21697720ff43b8dfa25b8e8d9ca7f56f4597fc80'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/26b6b14c7a0368e317a1e9fb5144ebe6f8d495cf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00165
epssPercentile: 0.05081
ingestedAt: '2026-09-17T16:21:47.756Z'
---

## Overview

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

esp: do not unref managed frag pages in esp_ssg_unref()

esp_ssg_unref() releases the page references held on the source
scatterlist after the AEAD operation completes.  It calls
skb_page_unref() on every frag page for an out-of-place transform
(req->src != req->dst), and in the error path of esp_output_tail()
(already_unref == true) on the request's own scatterlist.

This is wrong when the skb carries managed frags
(SKBFL_MANAGED_FRAG_REFS).  Managed frags are owned by a zerocopy ubuf
and the skb does not hold a per-frag page reference; io_uring SEND_ZC
with a registered buffer attaches the bvec pages this way via
io_sg_from_iter().  The rest of the stack honours this invariant:
skb_release_data() skips the per-frag unref when SKBFL_MANAGED_FRAG_REFS
is set, and skb_zcopy_managed() is the guard used at the other unref
sites.

esp_ssg_unref() is missing that guard, so for a managed-frag skb it
drops a page reference the skb never acquired.  This can underflow the
page reference count and free a page that is still in use.

Guard the function with skb_zcopy_managed() so both unref paths are
skipped for managed-frag skbs, matching skb_release_data().

## Remediation

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