On Fri, Sep 21, 2012 at 1:54 AM, Kees Cook <[email protected]> wrote:
> This adds a short description of the no_new_privs bit, as described in
> Documentation/prctl/no_new_privs.txt.
Thanks Kees. Applied.
Cheers,
Michael
> Signed-off-by: Kees Cook <[email protected]>
> ---
> man2/prctl.2 | 15 +++++++++++++++
> 1 files changed, 15 insertions(+), 0 deletions(-)
>
> diff --git a/man2/prctl.2 b/man2/prctl.2
> index a44aa32..220c031 100644
> --- a/man2/prctl.2
> +++ b/man2/prctl.2
> @@ -42,6 +42,7 @@
> .\" 2012-04-25 Michael Kerrisk, Document PR_TASK_PERF_EVENTS_DISABLE and
> .\" PR_TASK_PERF_EVENTS_ENABLE
> .\" 2012-09-20 Kees Cook, update PR_SET_SECCOMP for mode 2
> +.\" 2012-09-20 Kees Cook, document PR_SET_NO_NEW_PRIVS, PR_GET_NO_NEW_PRIVS
> .\"
> .\" FIXME: Document PR_SET_TIMERSLACK and PR_GET_TIMERSLACK (new in 2.6.28)
> .\" commit 6976675d94042fbd446231d1bd8b7de71a980ada
> @@ -216,6 +217,19 @@ in the buffer pointed to by
> The buffer should allow space for up to 16 bytes;
> the returned string will be null-terminated if it is shorter than that.
> .TP
> +.BR PR_SET_NO_NEW_PRIVS " (since Linux 3.5)"
> +Set the current process's \fIno_new_privs\fP bit to the value in
> +\fIarg2\fP. With \fIno_new_privs\fP set to 1, execve promises not
> +to grant the privilege to do anything that could not have been done
> +without the execve call (for example, rendering setuid, setgid, and file
> +capabilities non-functional). When enabled, this value is inherited
> +across fork, clone, and execve and cannot be unset.
> +.TP
> +.BR PR_GET_NO_NEW_PRIVS " (since Linux 3.5)"
> +Return the value of the \fIno_new_privs\fP bit for the current process. A
> +value of 0 indicates the regular execve behavior. A value of 1 indicates
> +execve will operate in the privilege restricting mode described above.
> +.TP
> .BR PR_SET_PDEATHSIG " (since Linux 2.1.57)"
> Set the parent process death signal
> of the calling process to \fIarg2\fP (either a signal value
> @@ -567,6 +581,7 @@ option.
> On success,
> .BR PR_GET_DUMPABLE ,
> .BR PR_GET_KEEPCAPS ,
> +.BR PR_GET_NO_NEW_PRIVS ,
> .BR PR_CAPBSET_READ ,
> .BR PR_GET_TIMING ,
> .BR PR_GET_SECUREBITS ,
> --
> 1.7.0.4
>
>
> --
> Kees Cook
> Chrome OS Security
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Author of "The Linux Programming Interface"; http://man7.org/tlpi/