privatetmp

PrivateTmp is a Linux kernel command line argument that restricts the process to use only its own private temporary file system hierarchy instead of the shared one.

When set, PrivateTmp prevents the process from accessing files in the shared /tmp directory, but instead uses its own dedicated temporary directory. This is achieved by embedding the process's PID into the root of the temporary directory, creating a unique and isolated file system hierarchy for the process.

PrivateTmp is commonly used in security and system administration contexts to isolate processes from each other, preventing them from reading, writing, or modifying files created by other processes. This can help mitigate risks associated with shared files, such as the spreading of malware or the exposure of sensitive information.

PrivateTmp is typically used in conjunction with other security measures, such as SELinux or AppArmor, to provide an additional layer of security. It can be specified on a system-wide basis, but also per-process through the use of systemd services.

In terms of performance, PrivateTmp can introduce some overhead due to the creation of a new file system hierarchy for each process. However, the impact is typically minimal, and the benefits of additional security and isolation often outweigh any potential performance costs.

Overall, PrivateTmp provides a useful security feature for Linux system administrators, allowing for greater control over process isolation and the protection of shared file systems. By providing a dedicated temporary directory for each process, it helps to mitigate risks associated with shared files and promotes a more secure and reliable system.