svn commit: r290324 - stable/10/sys/kern

[Konstantin Belousov]

Author: kib
Date: Tue Nov  3 08:31:01 2015
New Revision: 290324
URL: https://svnweb.freebsd.org/changeset/base/290324

Log:
  MFC r289660,r289664:
  Do not allow to execute ptrace(PT_TRACE_ME) when the process is
  already traced or when there is no parent which can trace the process.

Modified:
  stable/10/sys/kern/sys_process.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/sys_process.c
==============================================================================
--- stable/10/sys/kern/sys_process.c	Tue Nov  3 08:28:47 2015	(r290323)
+++ stable/10/sys/kern/sys_process.c	Tue Nov  3 08:31:01 2015	(r290324)
@@ -442,7 +442,7 @@ ptrace_vm_entry(struct thread *td, struc
 }
 
 #ifdef COMPAT_FREEBSD32
-static int      
+static int
 ptrace_vm_entry32(struct thread *td, struct proc *p,
     struct ptrace_vm_entry32 *pve32)
 {
@@ -743,7 +743,18 @@ 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: