svn commit: r185385 - head/sys/kern

[Ed Schouten]

Author: ed
Date: Fri Nov 28 14:53:18 2008
New Revision: 185385
URL: http://svn.freebsd.org/changeset/base/185385

Log:
  Fix matching of message queues by name.
  
  The mqfs_search() routine uses strncmp() to match message queue objects
  by name. This is because it can be called from environments where the
  file name is not null terminated (the VFS for example).
  
  Unfortunately it doesn't compare the lengths of the message queue names,
  which means if a system has "Queue12345", the name "Queue" will also
  match.
  
  I noticed this when a student of mine handed in an exercise using
  message queues with names "Queue2" and "Queue".
  
  Reviewed by:	rink

Modified:
  head/sys/kern/uipc_mqueue.c

Modified: head/sys/kern/uipc_mqueue.c
==============================================================================
--- head/sys/kern/uipc_mqueue.c	Fri Nov 28 14:49:26 2008	(r185384)
+++ head/sys/kern/uipc_mqueue.c	Fri Nov 28 14:53:18 2008	(r185385)
@@ -793,7 +793,8 @@ mqfs_search(struct mqfs_node *pd, const 
 
 	sx_assert(&pd->mn_info->mi_lock, SX_LOCKED);
 	LIST_FOREACH(pn, &pd->mn_children, mn_sibling) {
-		if (strncmp(pn->mn_name, name, len) == 0)
+		if (strncmp(pn->mn_name, name, len) == 0 &&
+		    pn->mn_name[len] == '\0')
 			return (pn);
 	}
 	return (NULL);