git: daf8ad192942 - releng/14.0 - p_candebug(9): cr_bsd_visible() impacts, misc fixes
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Date: Wed, 18 Oct 2023 18:03:52 UTC
The branch releng/14.0 has been updated by mhorne: URL: https://cgit.FreeBSD.org/src/commit/?id=daf8ad192942f6d9da1affca6a0ea9d3da42101f commit daf8ad192942f6d9da1affca6a0ea9d3da42101f Author: Olivier Certner <olce.freebsd@certner.fr> AuthorDate: 2023-08-17 23:54:43 +0000 Commit: Mitchell Horne <mhorne@FreeBSD.org> CommitDate: 2023-10-18 18:01:26 +0000 p_candebug(9): cr_bsd_visible() impacts, misc fixes Mention cr_bsd_visible(9). Remove references to cr_canseeothergids(9) and cr_canseeotheruids(9), as well as indirect references not immediately useful. Fix description of credentials checks to match reality. Re-order errors to match code's check order. Approved by: re (gjb) Reviewed by: bcr, pauamma_gundo.com Sponsored by: Kumacom SAS Differential Revision: https://reviews.freebsd.org/D40638 (cherry picked from commit eb94f24fab4b44f13ca045370d9fcf12ca8835f2) (cherry picked from commit c29ee9e238b36ef8a7c4508582d4512cda885192) --- share/man/man9/p_candebug.9 | 103 ++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 47 deletions(-) diff --git a/share/man/man9/p_candebug.9 b/share/man/man9/p_candebug.9 index e80d313de55c..c824db974154 100644 --- a/share/man/man9/p_candebug.9 +++ b/share/man/man9/p_candebug.9 @@ -1,5 +1,6 @@ .\" .\" Copyright (c) 2003 Joseph Koshy <jkoshy@FreeBSD.org> +.\" Copyright (c) 2023 Olivier Certner <olce.freebsd@certner.fr> .\" .\" All rights reserved. .\" @@ -25,7 +26,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.Dd November 19, 2006 +.Dd August 18, 2023 .Dt P_CANDEBUG 9 .Os .Sh NAME @@ -37,24 +38,27 @@ .Ft int .Fn p_candebug "struct thread *td" "struct proc *p" .Sh DESCRIPTION -This function can be used to determine if a given process +This function determines if a given process .Fa p -is debuggable by the thread +is debuggable by some thread .Fa td . -.Sh SYSCTL VARIABLES +.Pp The following .Xr sysctl 8 variables directly influence the behaviour of .Fn p_candebug : .Bl -tag -width indent +.It Va security.bsd.unprivileged_proc_debug +Must be set to a non-zero value to allow unprivileged processes +access to the kernel's debug facilities. .It Va kern.securelevel Debugging of the init process is not allowed if this variable is .Li 1 or greater. -.It Va security.bsd.unprivileged_proc_debug -Must be set to a non-zero value to allow unprivileged processes -access to the kernel's debug facilities. .El +.Pp +Other such variables indirectly influence it; see +.Xr cr_bsd_visible 9 . .Sh RETURN VALUES The .Fn p_candebug @@ -68,35 +72,45 @@ is debuggable by thread or a non-zero error return value otherwise. .Sh ERRORS .Bl -tag -width Er -.It Bq Er EACCESS -The MAC subsystem denied debuggability. -.It Bq Er EAGAIN -Process -.Fa p -is in the process of being -.Fn exec Ns 'ed. .It Bq Er EPERM +An unprivileged process attempted to debug another process but the system is +configured to deny it +.Po +see +.Xr sysctl 8 +variable +.Va security.bsd.unprivileged_proc_debug +above +.Pc . +.It Bq Er ESRCH Thread .Fa td -lacks super-user credentials and process -.Fa p -is executing a set-user-ID or set-group-ID executable. +has been jailed and the process to debug does not belong to the same jail or one +of its sub-jails, as determined by +.Xr prison_check 9 . +.It Bq Er ESRCH +.Xr cr_bsd_visible 9 +denied visibility according to the BSD security policies in force. .It Bq Er EPERM Thread .Fa td -lacks super-user credentials and process +lacks superuser credentials and its (effective) group set is not a superset of +process .Fa p Ns 's -group set is not a subset of -.Fa td Ns 's -effective group set. +whole group set +.Pq "including real, effective and saved group IDs" . .It Bq Er EPERM Thread .Fa td -lacks super-user credentials and process -.Fa p Ns 's -user IDs do not match thread -.Fa td Ns 's -effective user ID. +lacks superuser credentials and its (effective) user ID does not match all user +IDs of process +.Fa p . +.It Bq Er EPERM +Thread +.Fa td +lacks superuser credentials and process +.Fa p +is executing a set-user-ID or set-group-ID executable. .It Bq Er EPERM Process .Fa p @@ -107,30 +121,25 @@ and the variable .Va kern.securelevel is greater than zero. -.It Bq Er ESRCH +.It Bq Er EBUSY Process .Fa p -is not visible to thread -.Fa td -as determined by -.Xr cr_canseeotheruids 9 -or -.Xr cr_canseeothergids 9 . -.It Bq Er ESRCH -Thread -.Fa td -has been jailed and process +is in the process of being +.Fn exec Ns 'ed. +.It Bq Er EPERM +Process .Fa p -does not belong to the same jail as -.Fa td . -.It Bq Er ESRCH -The MAC subsystem denied debuggability. +denied debuggability +.Po +see +.Xr procctl 2 , +command +.Dv PROC_TRACE_CTL +.Pc . .El .Sh SEE ALSO -.Xr jail 2 , -.Xr sysctl 8 , -.Xr cr_canseeothergids 9 , -.Xr cr_canseeotheruids 9 , +.Xr prison_check 9 , .Xr mac 9 , -.Xr p_cansee 9 , -.Xr prison_check 9 +.Xr cr_bsd_visible 9 , +.Xr procctl 2 , +.Xr p_cansee 9