svn commit: r277197 - user/dchagin/lemul/sys/compat/linux

[Dmitry Chagin]

Author: dchagin
Date: Wed Jan 14 22:05:28 2015
New Revision: 277197
URL: https://svnweb.freebsd.org/changeset/base/277197

Log:
  In the case of an "that ugly way" when we try to find Linux thread by
  pfind() check that the returned process is a Linux process. Otherwise,
  below we dereference em pointer expecting it points to a Linux thread.
  
  Reported by:    trinity

Modified:
  user/dchagin/lemul/sys/compat/linux/linux_misc.c

Modified: user/dchagin/lemul/sys/compat/linux/linux_misc.c
==============================================================================
--- user/dchagin/lemul/sys/compat/linux/linux_misc.c	Wed Jan 14 21:39:31 2015	(r277196)
+++ user/dchagin/lemul/sys/compat/linux/linux_misc.c	Wed Jan 14 22:05:28 2015	(r277197)
@@ -2004,6 +2004,7 @@ linux_sched_rr_get_interval(struct threa
 struct thread *
 linux_tdfind(struct thread *td, lwpid_t tid, pid_t pid)
 {
+	struct linux_pemuldata *pem;
 	struct linux_emuldata *em;
 	struct thread *tdt;
 	struct proc *p;
@@ -2020,6 +2021,14 @@ linux_tdfind(struct thread *td, lwpid_t 
 		 */
 		p = pfind(tid);
 		if (p) {
+			pem = pem_find(p);
+			if (pem == NULL) {
+				/*
+				 * p is not a Linuxulator process.
+				 */
+				PROC_UNLOCK(p);
+				return (NULL);
+			}
 			FOREACH_THREAD_IN_PROC(p, tdt) {
 				em = em_find(tdt);
 				if (tid == em->em_tid)