svn commit: r289660 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Tue Oct 20 20:22:57 2015
New Revision: 289660
URL: https://svnweb.freebsd.org/changeset/base/289660

Log:
  Reviewed by:	jhb, pho
  Reported and tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	2 weeks
  Differential revision:	https://reviews.freebsd.org/D3908

Modified:
  head/sys/kern/sys_process.c

Modified: head/sys/kern/sys_process.c
==============================================================================
--- head/sys/kern/sys_process.c	Tue Oct 20 20:15:25 2015	(r289659)
+++ head/sys/kern/sys_process.c	Tue Oct 20 20:22:57 2015	(r289660)
@@ -744,7 +744,18 @@ kern_ptrace(struct thread *td, int req, 
 	 */
 	switch (req) {
 	case PT_TRACE_ME:
-		/* Always legal. */
+		/*
+		 * Always legal, when there is a parent process which
+		 * could trace us.  Otherwise, reject.
+		 */
+		if ((p->p_flag & P_TRACED) != 0) {
+			error = EBUSY;
+			goto fail;
+		}
+		if (p->p_pptr == initproc) {
+			error = EPERM;
+			goto fail;
+		}
 		break;
 
 	case PT_ATTACH: