CVE-2019-16413

Public on

Last Modified: UTC

Description

A flaw was found in the implementation of the 9p filesystem in the Linux kernel. The 9p filesystem does not protect i_size_write() properly, which causes an i_size_read() infinite loop. An attacker, able to mount a specially crafted filesystem, could cause a denial of service on SMP systems.

A flaw was found in the implementation of the 9p filesystem in the Linux kernel. The 9p filesystem does not protect i_size_write() properly, which causes an i_size_read() infinite loop. An attacker, able to mount a specially crafted filesystem, could cause a denial of service on SMP systems.

Mitigation

As the 9p module will be auto-loaded when required, its use can be disabled by preventing the module from loading with the following instructions:

# echo "install 9p /bin/true" >> /etc/modprobe.d/disable-9p.conf

The system will need to be restarted if the 9p modules are loaded. In most circumstances, the 9p kernel modules will be unable to be unloaded while the filesystems are in use.

If the system requires this module to work correctly, this mitigation may not be suitable.

If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.

Additional information

  • Bugzilla 1757321: kernel: i_size_read() infinite loop leads to denial of service
  • CWE-835->CWE-400: Loop with Unreachable Exit Condition ('Infinite Loop') leads to Uncontrolled Resource Consumption
  • FAQ: Frequently asked questions about CVE-2019-16413

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

6.2

7.5

Attack Vector

Local

Network

Attack Complexity

Low

Low

Privileges Required

None

None

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

None

None

Integrity Impact

None

None

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

My product is listed as "Out of Support Scope". What does this mean?

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