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PRIV_WRAPPER(1)   PRIV_WRAPPER(1)

NAME

priv_wrapper - A library to disable resource limits and other priviledge dropping.

SYNOPSIS

LD_PRELOAD=libpriv_wrapper.so PRIV_WRAPPER=1 [PRIV_WRAPPER_CHROOT_DISABLE=1] [PRIV_WRAPPER_PRCTL_DISABLE=<options>] [PRIV_WRAPPER_SETRLIMIT_DISABLE=<options>]

DESCRIPTION

priv_wrapper aims to help running processes which are dropping privileges or are restricting resources in test environments. It can disable chroot, prctl, pledge and setrlmit system calls. A disabled call always succeeds (i.e. returns 0) and does nothing. The system call pledge exists only on OpenBSD.

ENVIRONMENT VARIABLES

PRIV_WRAPPER

This variable activates priv_wrapper when set to 1.

PRIV_WRAPPER_DISABLE_DEEPBIND

This allows you to disable deep binding in priv_wrapper. This is useful for running valgrind tools or sanitizers like (address, undefined, thread).

PRIV_WRAPPER_CHROOT_DISABLE

If this is set to 1 then chroot() system call will be disabled.

PRIV_WRAPPER_PRCTL_DISABLE

prctl calls can be disabled using this environment variable. You can either disable all calls using PRIV_WRAPPER_PRCTL_DISABLE=ALL or special options using e.g. PRIV_WRAPPER_PRCTL_DISABLE=PR_SET_SECCOMP|PR_SET_NO_NEW_PRIVS

Supported options are:

PR_SET_SECCOMP PR_SET_NO_NEW_PRIVS PR_SET_DUMPABLE

PRIV_WRAPPER_SETRLIMIT_DISABLE

Either all resource limits can be disabled using PRIV_WRAPPER_SETRLIMIT_DISABLE=ALL or you can pick specific resources using e.g:

PRIV_WRAPPER_SETRLIMIT_DISABLE=RLIMIT_STACK|RLIMIT_CORE

Supported options are:

RLIMIT_CPU RLIMIT_FSIZE RLIMIT_DATA RLIMIT_STACK RLIMIT_CORE RLIMIT_RSS RLIMIT_NOFILE RLIMIT_AS RLIMIT_NPROC RLIMIT_MEMLOCK RLIMIT_LOCKS RLIMIT_SIGPENDING RLIMIT_MSGQUEUE RLIMIT_NICE RLIMIT_RTPRIO RLIMIT_RTTIME RLIMIT_NLIMITS

PRIV_WRAPPER_PLEDGE_DISABLE

If this is set to 1 then pledge() system call will be disabled.

PRIV_WRAPPER_DEBUGLEVEL

If you need to see what is going on in priv_wrapper itself or try to find a bug, you can enable logging support in priv_wrapper if you built it with debug symbols.

•0 = ERROR

•1 = WARNING

•2 = DEBUG

•3 = TRACE

EXAMPLE

LD_PRELOAD=libpriv_wrapper.so PRIV_WRAPPER=1 PRIV_WRAPPER_PRCTL_DISABLE="PR_SET_SECCOMP|PR_SET_NO_NEW_PRIVS"

LD_PRELOAD=libpriv_wrapper.so PRIV_WRAPPER=1 PRIV_WRAPPER_CHROOT_DISABLE=1 PRIV_WRAPPER_PRCTL_DISABLE=ALL PRIV_WRAPPER_SETRLIMIT_DISABLE="RLIMIT_CPU|RLIMIT_DATA|RLIMIT_NLIMITS"

AUTHOR

Samba Team

2022-09-14