CVE-2017-12190

Severity CVSS v4.0:

Pending analysis

Type:

CWE-400 Uncontrolled Resource Consumption ('Resource Exhaustion')

Publication date:

22/11/2017

Last modified:

20/04/2025

Description

The bio_map_user_iov and bio_unmap_user functions in block/bio.c in the Linux kernel before 4.13.8 do unbalanced refcounting when a SCSI I/O vector has small consecutive buffers belonging to the same page. The bio_add_pc_page function merges them into one, but the page reference is never dropped. This causes a memory leak and possible system lockup (exploitable against the host OS by a guest OS user, if a SCSI disk is passed through to a virtual machine) due to an out-of-memory condition.

Impact

Vector 3.x

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 6.50 MEDIUM
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x

6.50

Severity 3.x

MEDIUM

Vector 2.0

AV:L/AC:L/Au:N/C:N/I:N/A:C CVSS v2.0 Severity and Metrics:

Base Score: 4.90 MEDIUM
Vector: AV:L/AC:L/Au:N/C:N/I:N/A:C

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): None
Integrity (I): None
Availability (A): Complete