avc_sid_stats - Linux

Overview

avc_sid_stats is a Linux command that provides detailed statistics about Security-Enhanced Linux (SELinux) access vector cache (AVC) Security Identifier (SID) usage. It helps administrators analyze the AVC cache performance, identify potential bottlenecks, and improve the overall SELinux security posture.

Syntax

avc_sid_stats [-h] [-a] [-n] [-s] [-t] [-x] [-v]

Options/Flags

  • -h, –help: Display this help message.
  • -a, –all: Include disabled SIDs in the statistics.
  • -n, –no-header: Do not print the headers in the output.
  • -s, –sort: Sort the output by the specified field (default: "sid").
  • -t, –table: Output the statistics in a table format.
  • -x, –xml: Output the statistics in XML format.
  • -v, –version: Display the command version.

Examples

List AVC SID statistics

avc_sid_stats

Sort output by number of AVC invocations

avc_sid_stats -s access_count

Display statistics in XML format

avc_sid_stats -x

Filter for disabled SIDs

avc_sid_stats -a

Common Issues

  • No statistics are displayed: Ensure that the AVC cache is enabled and that the kernel is logging AVC denials.
  • Output is too verbose: Use the -n option to suppress the header rows.
  • XML output is malformed: Check the kernel version. Some older versions may have issues generating valid XML output.

Integration

avc_sid_stats can be integrated with other SELinux tools for advanced analysis. For example:

# Identify the most frequently accessed SIDs
avc_sid_stats -s access_count | head -n 10

# Count the total number of AVC denials for a specific SID
avc_sid_stats | grep 'my_sid' | awk '{print $3}'

Related Commands

  • dmesg: Display kernel log messages.
  • auditctl: Manage SELinux auditing configuration.
  • sealert: Analyze and report SELinux audit events.