svn commit: r236286 - head/usr.bin/mail

[Eitan Adler]

Author: eadler
Date: Wed May 30 03:55:44 2012
New Revision: 236286
URL: http://svn.freebsd.org/changeset/base/236286

Log:
  Fix likely race condition if wait_child() is interrupted by sigchild()
  
  PR:		bin/102834
  Submitted by:	Andreas Longwitz <longwitz at incore.de>
  Approved by:	cperciva
  MFC after:	2 weeks

Modified:
  head/usr.bin/mail/popen.c

Modified: head/usr.bin/mail/popen.c
==============================================================================
--- head/usr.bin/mail/popen.c	Wed May 30 03:54:10 2012	(r236285)
+++ head/usr.bin/mail/popen.c	Wed May 30 03:55:44 2012	(r236286)
@@ -336,12 +336,14 @@ int
 wait_child(int pid)
 {
 	sigset_t nset, oset;
-	struct child *cp = findchild(pid);
+	struct child *cp;
 
 	(void)sigemptyset(&nset);
 	(void)sigaddset(&nset, SIGCHLD);
 	(void)sigprocmask(SIG_BLOCK, &nset, &oset);	
 
+	cp = findchild(pid);
+
 	while (!cp->done)
 		(void)sigsuspend(&oset);
 	wait_status = cp->status;