---
id: CVE-2026-90011
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  scsi: target: iscsi: Reserve a terminator byte for the login payload

  iscsi_target_check_login_request() rejects a login PDU whose
  DataSegmentLength exceeds MAX_KEY_VAL…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  scsi: target: iscsi: Reserve a terminator byte for the login payload

  iscsi_target_check_login_request() rejects a login PDU whose
  DataSegmentLength exceeds MAX_KEY_VAL…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    5fac79f248c37774d1dd761406f83d25ca6ff8e4
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    6ddddcad436d8e6e619204d3c848147ff2f5bf1e
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    b19dc17ed963ac36c0db4b52a1803fb11169f91f
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    6b589ef9d5f6cdc70d2b4f269ca6cf26b5ebb076
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    eb9dadf4d552ebe10644871c5189286552aa48f5
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    1624bff4c5118ad494d50ad94d44f22064667a7f
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    3ddf3ea291a0ef2ea93b82e158960ac2cc42302b
  - >-
    Linux >= e48354ce078c079996f89d715dfa44814b4eba01 <
    f4825922d2fb371e2b969697d792077f1b62b62c
  - Linux 3.1
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:18:24.763'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90011'
references:
  - url: 'https://git.kernel.org/stable/c/1624bff4c5118ad494d50ad94d44f22064667a7f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3ddf3ea291a0ef2ea93b82e158960ac2cc42302b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5fac79f248c37774d1dd761406f83d25ca6ff8e4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6b589ef9d5f6cdc70d2b4f269ca6cf26b5ebb076'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6ddddcad436d8e6e619204d3c848147ff2f5bf1e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b19dc17ed963ac36c0db4b52a1803fb11169f91f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eb9dadf4d552ebe10644871c5189286552aa48f5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f4825922d2fb371e2b969697d792077f1b62b62c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-16T10:53:53.942Z'
epss: 0.00866
epssPercentile: 0.56946
---

## Overview

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

scsi: target: iscsi: Reserve a terminator byte for the login payload

iscsi_target_check_login_request() rejects a login PDU whose
DataSegmentLength exceeds MAX_KEY_VALUE_PAIRS, but the test is '>' and
login->req_buf is allocated with exactly MAX_KEY_VALUE_PAIRS
bytes. Since iscsit_get_login_rx() receives payload_length + padding
bytes, where

	padding = ((-payload_length) & 3);

any payload_length from 8189 to 8192 fills the whole 8192 byte
buffer. The write stays in bounds, but no byte is left for a NUL
terminator.

The buffer is subsequently consumed as a C string. In the CHAP path
chap_check_algorithm() calls kstrdup(a_str), and extract_param() calls
strstr(in_buf, pattern) followed by strlen_semi(), none of which take a
length. convert_null_to_semi() additionally rewrites every embedded NUL
to ';', so even a payload made of well formed NUL separated key=value
records is left without a terminator. These walk past the end of the
object into adjacent slab memory. It is reachable by an unauthenticated
initiator against a portal configured for CHAP; when authentication is
not required iscsi_login_zero_tsih_s2() rewrites AuthMethod to None and
the CHAP path is never entered.

Allocate one extra byte. kzalloc() zeroes it and nothing ever writes to
it, as every writer copies to offset 0 for at most MAX_KEY_VALUE_PAIRS
bytes, so the buffer is always terminated.

## Remediation

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