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.

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 18 Sep 2026 08:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-788

Wed, 16 Sep 2026 14:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'}


Wed, 16 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Description 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.
Title scsi: target: iscsi: Reserve a terminator byte for the login payload
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T08:56:25.054Z

Reserved: 2026-09-11T19:38:34.781Z

Link: CVE-2026-90011

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-16T11:17:13.760

Modified: 2026-10-19T09:18:48.927

Link: CVE-2026-90011

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-19T15:45:16Z

Weaknesses