---
id: CVE-2025-38700
title: 'scsi: libiscsi: Initialize iscsi_conn->dd_data only if memory is allocated'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  scsi: libiscsi: Initialize iscsi_conn->dd_data only if memory is allocated

  In case of an ib_fast_reg_mr allocation failure during iSER setup, the
  machine hits a panic …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    f53af99f441ee79599d8df6113a7144d74cf9153
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    9ea6d961566c7d762ed0204b06db05756fdda3b6
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    fd5aad080edb501ab5c84b7623d612d0e3033403
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    a145c269dc5380c063a20a0db7e6df2995962e9d
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    66a373f50b4249d57f5a88c7be9676f9d5884865
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    35782c32528d82aa21f84cb5ceb2abd3526a8159
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    a33d42b7fc24fe03f239fbb0880dd5b4b4b97c19
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    2b242ea14386a510010eabfbfc3ce81a101f3802
  - >-
    Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 <
    3ea3a256ed81f95ab0f3281a0e234b01a9cae605
  - Linux 2.6.27
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T21:07:38.309739Z'
published: '2025-09-04'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:12:53.632Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-38700'
references:
  - url: 'https://git.kernel.org/stable/c/f53af99f441ee79599d8df6113a7144d74cf9153'
  - url: 'https://git.kernel.org/stable/c/9ea6d961566c7d762ed0204b06db05756fdda3b6'
  - url: 'https://git.kernel.org/stable/c/fd5aad080edb501ab5c84b7623d612d0e3033403'
  - url: 'https://git.kernel.org/stable/c/a145c269dc5380c063a20a0db7e6df2995962e9d'
  - url: 'https://git.kernel.org/stable/c/66a373f50b4249d57f5a88c7be9676f9d5884865'
  - url: 'https://git.kernel.org/stable/c/35782c32528d82aa21f84cb5ceb2abd3526a8159'
  - url: 'https://git.kernel.org/stable/c/a33d42b7fc24fe03f239fbb0880dd5b4b4b97c19'
  - url: 'https://git.kernel.org/stable/c/2b242ea14386a510010eabfbfc3ce81a101f3802'
  - url: 'https://git.kernel.org/stable/c/3ea3a256ed81f95ab0f3281a0e234b01a9cae605'
tags:
  - cve.org
epss: 0.00183
epssPercentile: 0.0793
ingestedAt: '2026-11-05T22:38:32.014Z'
---

## Overview

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

scsi: libiscsi: Initialize iscsi_conn->dd_data only if memory is allocated

In case of an ib_fast_reg_mr allocation failure during iSER setup, the
machine hits a panic because iscsi_conn->dd_data is initialized
unconditionally, even when no memory is allocated (dd_size == 0).  This
leads invalid pointer dereference during connection teardown.

Fix by setting iscsi_conn->dd_data only if memory is actually allocated.

Panic trace:
------------
 iser: iser_create_fastreg_desc: Failed to allocate ib_fast_reg_mr err=-12
 iser: iser_alloc_rx_descriptors: failed allocating rx descriptors / data buffers
 BUG: unable to handle page fault for address: fffffffffffffff8
 RIP: 0010:swake_up_locked.part.5+0xa/0x40
 Call Trace:
  complete+0x31/0x40
  iscsi_iser_conn_stop+0x88/0xb0 [ib_iser]
  iscsi_stop_conn+0x66/0xc0 [scsi_transport_iscsi]
  iscsi_if_stop_conn+0x14a/0x150 [scsi_transport_iscsi]
  iscsi_if_rx+0x1135/0x1834 [scsi_transport_iscsi]
  ? netlink_lookup+0x12f/0x1b0
  ? netlink_deliver_tap+0x2c/0x200
  netlink_unicast+0x1ab/0x280
  netlink_sendmsg+0x257/0x4f0
  ? _copy_from_user+0x29/0x60
  sock_sendmsg+0x5f/0x70

## Affected

- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < f53af99f441ee79599d8df6113a7144d74cf9153`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < 9ea6d961566c7d762ed0204b06db05756fdda3b6`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < fd5aad080edb501ab5c84b7623d612d0e3033403`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < a145c269dc5380c063a20a0db7e6df2995962e9d`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < 66a373f50b4249d57f5a88c7be9676f9d5884865`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < 35782c32528d82aa21f84cb5ceb2abd3526a8159`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < a33d42b7fc24fe03f239fbb0880dd5b4b4b97c19`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < 2b242ea14386a510010eabfbfc3ce81a101f3802`
- `Linux >= 5d91e209fb21fb9cc765729d4c6a85a9fb6c9187 < 3ea3a256ed81f95ab0f3281a0e234b01a9cae605`
- `Linux 2.6.27`

## Remediation

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