CVE Vulnerabilities

CVE-2018-12232

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Published: Jun 12, 2018 | Modified: Nov 21, 2024
CVSS 3.x
5.9
MEDIUM
Source:
NVD
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
7.1 HIGH
AV:N/AC:M/Au:N/C:N/I:N/A:C
RedHat/V2
RedHat/V3
5.5 MODERATE
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Ubuntu
MEDIUM

In net/socket.c in the Linux kernel through 4.17.1, there is a race condition between fchownat and close in cases where they target the same socket file descriptor, related to the sock_close and sockfs_setattr functions. fchownat does not increment the file descriptor reference count, which allows close to set the socket to NULL during fchownats execution, leading to a NULL pointer dereference and system crash.

Weakness

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Software

Name Vendor Start Version End Version
Linux_kernel Linux * 4.17.1 (including)
Red Hat Enterprise Linux 7 RedHat kernel-alt-0:4.14.0-115.el7a *
Linux Ubuntu artful *
Linux Ubuntu bionic *
Linux Ubuntu esm-infra/bionic *
Linux Ubuntu precise/esm *
Linux Ubuntu upstream *
Linux-aws Ubuntu bionic *
Linux-aws Ubuntu esm-infra/bionic *
Linux-aws Ubuntu upstream *
Linux-azure Ubuntu bionic *
Linux-azure Ubuntu esm-infra/bionic *
Linux-azure Ubuntu esm-infra/xenial *
Linux-azure Ubuntu upstream *
Linux-azure Ubuntu xenial *
Linux-azure-edge Ubuntu upstream *
Linux-azure-edge Ubuntu xenial *
Linux-euclid Ubuntu upstream *
Linux-euclid Ubuntu xenial *
Linux-flo Ubuntu trusty *
Linux-flo Ubuntu upstream *
Linux-flo Ubuntu xenial *
Linux-gcp Ubuntu bionic *
Linux-gcp Ubuntu esm-infra/bionic *
Linux-gcp Ubuntu esm-infra/xenial *
Linux-gcp Ubuntu upstream *
Linux-gcp Ubuntu xenial *
Linux-gke Ubuntu upstream *
Linux-gke Ubuntu xenial *
Linux-goldfish Ubuntu trusty *
Linux-goldfish Ubuntu upstream *
Linux-goldfish Ubuntu xenial *
Linux-grouper Ubuntu trusty *
Linux-grouper Ubuntu upstream *
Linux-hwe Ubuntu esm-infra/xenial *
Linux-hwe Ubuntu upstream *
Linux-hwe Ubuntu xenial *
Linux-hwe-edge Ubuntu esm-infra/xenial *
Linux-hwe-edge Ubuntu upstream *
Linux-hwe-edge Ubuntu xenial *
Linux-kvm Ubuntu bionic *
Linux-kvm Ubuntu esm-infra/bionic *
Linux-kvm Ubuntu upstream *
Linux-lts-trusty Ubuntu precise/esm *
Linux-lts-trusty Ubuntu upstream *
Linux-lts-utopic Ubuntu trusty *
Linux-lts-utopic Ubuntu upstream *
Linux-lts-vivid Ubuntu trusty *
Linux-lts-vivid Ubuntu upstream *
Linux-lts-wily Ubuntu trusty *
Linux-lts-wily Ubuntu upstream *
Linux-lts-xenial Ubuntu upstream *
Linux-maguro Ubuntu trusty *
Linux-maguro Ubuntu upstream *
Linux-mako Ubuntu trusty *
Linux-mako Ubuntu upstream *
Linux-mako Ubuntu xenial *
Linux-manta Ubuntu trusty *
Linux-manta Ubuntu upstream *
Linux-oem Ubuntu bionic *
Linux-oem Ubuntu esm-infra/bionic *
Linux-oem Ubuntu upstream *
Linux-oem Ubuntu xenial *
Linux-raspi2 Ubuntu artful *
Linux-raspi2 Ubuntu bionic *
Linux-raspi2 Ubuntu upstream *
Linux-snapdragon Ubuntu artful *
Linux-snapdragon Ubuntu upstream *

Extended Description

A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:

A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.

Potential Mitigations

  • Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
  • Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

References