capable(8)

NAME
capable - Trace security capability checks (cap_capable()).

SYNOPSIS
capable [-h] [-v] [-p PID] [-K] [-U] [-x] [--cgroupmap MAPPATH]
           [--mntnsmap MAPPATH] [--unique]

DESCRIPTION
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.

REQUIREMENTS
CONFIG_BPF, bcc.

OPTIONS
-h USAGE message.

-v  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.

-K  Include kernel stack traces to the output.

-U  Include user-space stack traces to the output.

-x  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).

--unique
    Don't repeat stacks for the same PID or cgroup.

EXAMPLES

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

FIELDS

TIME(s)
    Time of capability check: HH:MM:SS.

UID User ID.

PID Process ID.

COMM
    Process name. CAP Capability number. NAME Capability name. See capabilities(7) for descriptions.

AUDIT
    Whether this was an audit event. Use -v to include non-audit events. INSETID Whether the INSETID bit was set (Linux >= 5.1).

OVERHEAD
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.

SOURCE
This is from bcc.

    https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

OS
Linux

STABILITY
Unstable - in development.

AUTHOR
Brendan Gregg

SEE ALSO
capabilities(7)