capng_clear - Linux
Overview
capng_clear
is a command-line tool for manipulating capabilities in Linux using the newer capabilities API introduced in Linux 2.2. It allows you to clear all capabilities from a given process or thread, effectively reverting it to a state of minimal privilege.
Syntax
capng_clear [-h] [-g] [-p <pid>] [-t <tid>]
Options/Flags
- -h, –help: Display usage information.
- -g: Clear capabilities for all threads in the current process.
- -p
: Clear capabilities for the specified process ID ( <pid>
). - -t
: Clear capabilities for the specified thread ID ( <tid>
).
Examples
Simple Usage:
Clear all capabilities from the current process:
capng_clear
Clearing Capabilities for a Specific Process:
Clear capabilities for a process with PID 1234
:
capng_clear -p 1234
Clearing Capabilities for a Specific Thread:
Clear capabilities for a thread with TID 5678
:
capng_clear -t 5678
Common Issues
- Permission Denied: Ensure you have sufficient privileges (root or CAP_SETPCAP) to clear capabilities.
- Invalid PID or TID: Verify that the provided process or thread ID is valid.
Integration
capng_clear
can be used in combination with other commands to manage capabilities:
# Get current capabilities
getcapng -i <pid>
# Clear capabilities
capng_clear -p <pid>
# Set specific capabilities
setcapng -s <caplist> <pid>
Related Commands
getcapng
: Get capabilitiessetcapng
: Set capabilitiescapabilities
: Display capabilitiescap_get_proc
: Get capabilities for a specific file descriptorcap_set_proc
: Set capabilities for a specific file descriptor