|capable(8)||System Manager's Manual||capable(8)|
capable - Trace security capability checks (cap_capable()).
capable [-h] [-v] [-p PID] [-K] [-U] [-x] [--cgroupmap
[--mntnsmap MAPPATH] [--unique]
This traces security capability checks in the kernel, and prints details for each call. This can be useful for general debugging, and also security enforcement: determining a white list of capabilities an application needs.
Since this uses BPF, only the root user can use this tool.
-h USAGE message.
- Include non-audit capability checks. These are those deemed not interesting and not necessary to audit, such as CAP_SYS_ADMIN checks on memory allocation to affect the behavior of overcommit.
- Include kernel stack traces to the output.
- Include user-space stack traces to the output.
- Show extra fields in TID and INSETID columns.
- --cgroupmap MAPPATH
- Trace cgroups in this BPF map only (filtered in-kernel).
- --mntnsmap MAPPATH
- Trace mount namespaces in this BPF map only (filtered in-kernel).
- Don't repeat stacks for the same PID or cgroup.
- Trace all capability checks system-wide:
- # capable
- Trace capability checks for PID 181:
- # capable -p 181
- Trace capability checks in a set of cgroups only (see special_filtering.md
- from bcc sources for more details): # capable --cgroupmap /sys/fs/bpf/test01
- Time of capability check: HH:MM:SS.
- User ID.
- Process ID.
- Process name. CAP Capability number. NAME Capability name. See capabilities(7) for descriptions.
- Whether this was an audit event. Use -v to include non-audit events. INSETID Whether the INSETID bit was set (Linux >= 5.1).
This adds low-overhead instrumentation to capability checks, which are expected to be low frequency, however, that depends on the application. Test in a lab environment before use.
This is from bcc.
Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.
Unstable - in development.