---
id: CVE-2026-22998
title: 'nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec'
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec


  Commit efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid
  H2C PDU length")

  ad…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= f775f2621c2ac5cc3a0b3a64665dad4fb146e510 <
    baabe43a0edefac8cd7b981ff87f967f6034dafe
  - >-
    Linux >= 4cb3cf7177ae3666be7fb27d4ad4d72a295fb02d <
    76abc83a9d25593c2b7613c549413079c14a4686
  - >-
    Linux >= 2871aa407007f6f531fae181ad252486e022df42 <
    7d75570002929d20e40110d6b03e46202c9d1bc7
  - >-
    Linux >= 24e05760186dc070d3db190ca61efdbce23afc88 <
    fdecd3b6aac10d5a18d0dc500fe57f8648b66cd4
  - >-
    Linux >= efa56305908ba20de2104f1b8508c6a7401833be <
    3def5243150716be86599c2a1767c29c68838b6d
  - >-
    Linux >= efa56305908ba20de2104f1b8508c6a7401833be <
    374b095e265fa27465f34780e0eb162ff1bef913
  - >-
    Linux >= efa56305908ba20de2104f1b8508c6a7401833be <
    32b63acd78f577b332d976aa06b56e70d054cbba
  - Linux ee5e7632e981673f42a50ade25e71e612e543d9d
  - Linux 70154e8d015c9b4fb56c1a2ef1fc8b83d45c7f68
  - Linux >= 5.10.209 < 5.10.249
  - Linux >= 5.15.148 < 5.15.199
  - Linux >= 6.1.75 < 6.1.162
  - Linux >= 6.6.14 < 6.6.122
  - Linux >= 5.4.268 < 5.5
  - Linux >= 6.7.2 < 6.8
  - Linux 6.8
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-06-16T20:38:02.086283Z'
published: '2026-01-25'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T18:25:26.863Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-22998'
references:
  - url: 'https://git.kernel.org/stable/c/baabe43a0edefac8cd7b981ff87f967f6034dafe'
  - url: 'https://git.kernel.org/stable/c/76abc83a9d25593c2b7613c549413079c14a4686'
  - url: 'https://git.kernel.org/stable/c/7d75570002929d20e40110d6b03e46202c9d1bc7'
  - url: 'https://git.kernel.org/stable/c/fdecd3b6aac10d5a18d0dc500fe57f8648b66cd4'
  - url: 'https://git.kernel.org/stable/c/3def5243150716be86599c2a1767c29c68838b6d'
  - url: 'https://git.kernel.org/stable/c/374b095e265fa27465f34780e0eb162ff1bef913'
  - url: 'https://git.kernel.org/stable/c/32b63acd78f577b332d976aa06b56e70d054cbba'
tags:
  - cve.org
epss: 0.0079
epssPercentile: 0.55492
ingestedAt: '2026-10-19T18:35:50.112Z'
---

## Overview

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

nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec

Commit efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length")
added ttag bounds checking and data_offset
validation in nvmet_tcp_handle_h2c_data_pdu(), but it did not validate
whether the command's data structures (cmd->req.sg and cmd->iov) have
been properly initialized before processing H2C_DATA PDUs.

The nvmet_tcp_build_pdu_iovec() function dereferences these pointers
without NULL checks. This can be triggered by sending H2C_DATA PDU
immediately after the ICREQ/ICRESP handshake, before
sending a CONNECT command or NVMe write command.

Attack vectors that trigger NULL pointer dereferences:
1. H2C_DATA PDU sent before CONNECT → both pointers NULL
2. H2C_DATA PDU for READ command → cmd->req.sg allocated, cmd->iov NULL
3. H2C_DATA PDU for uninitialized command slot → both pointers NULL

The fix validates both cmd->req.sg and cmd->iov before calling
nvmet_tcp_build_pdu_iovec(). Both checks are required because:
- Uninitialized commands: both NULL
- READ commands: cmd->req.sg allocated, cmd->iov NULL
- WRITE commands: both allocated

## Affected

- `Linux >= f775f2621c2ac5cc3a0b3a64665dad4fb146e510 < baabe43a0edefac8cd7b981ff87f967f6034dafe`
- `Linux >= 4cb3cf7177ae3666be7fb27d4ad4d72a295fb02d < 76abc83a9d25593c2b7613c549413079c14a4686`
- `Linux >= 2871aa407007f6f531fae181ad252486e022df42 < 7d75570002929d20e40110d6b03e46202c9d1bc7`
- `Linux >= 24e05760186dc070d3db190ca61efdbce23afc88 < fdecd3b6aac10d5a18d0dc500fe57f8648b66cd4`
- `Linux >= efa56305908ba20de2104f1b8508c6a7401833be < 3def5243150716be86599c2a1767c29c68838b6d`
- `Linux >= efa56305908ba20de2104f1b8508c6a7401833be < 374b095e265fa27465f34780e0eb162ff1bef913`
- `Linux >= efa56305908ba20de2104f1b8508c6a7401833be < 32b63acd78f577b332d976aa06b56e70d054cbba`
- `Linux ee5e7632e981673f42a50ade25e71e612e543d9d`
- `Linux 70154e8d015c9b4fb56c1a2ef1fc8b83d45c7f68`
- `Linux >= 5.10.209 < 5.10.249`
- `Linux >= 5.15.148 < 5.15.199`
- `Linux >= 6.1.75 < 6.1.162`
- `Linux >= 6.6.14 < 6.6.122`
- `Linux >= 5.4.268 < 5.5`
- `Linux >= 6.7.2 < 6.8`
- `Linux 6.8`

## Remediation

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