CVE-2018-12232 : Vulnerability Insights and Analysis

A race condition in net/socket.c within the Linux kernel up to version 4.17.1 can lead to a system crash due to a NULL pointer dereference.

Understanding CVE-2018-12232

This CVE involves a race condition in the Linux kernel that affects the fchownat and close functions when operating on the same socket file descriptor.

What is CVE-2018-12232?

The issue is related to the sock_close and sockfs_setattr functions in the kernel.
During the execution of fchownat, the file descriptor reference count is not incremented, allowing close to set the socket to NULL, resulting in a system crash.

The Impact of CVE-2018-12232

Exploitation of this vulnerability can lead to a NULL pointer dereference and subsequent system crash.

Technical Details of CVE-2018-12232

This section provides more in-depth technical information about the CVE.

Vulnerability Description

A race condition between fchownat and close functions targeting the same socket file descriptor.
Lack of increment in the file descriptor reference count during fchownat execution.
Setting the socket to NULL by close during fchownat, causing a NULL pointer dereference.

Affected Systems and Versions

Linux kernel versions up to 4.17.1 are impacted by this vulnerability.

Exploitation Mechanism

Attackers can exploit the race condition to trigger a NULL pointer dereference and crash the system.

Mitigation and Prevention

Protecting systems from CVE-2018-12232 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches provided by the Linux kernel maintainers.
Monitor vendor advisories for updates and apply them promptly.

Long-Term Security Practices

Regularly update the Linux kernel to the latest stable version.
Implement secure coding practices to prevent race conditions and NULL pointer dereferences.

Patching and Updates

Stay informed about security updates from Linux kernel vendors.
Apply patches and updates as soon as they are available.