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From: Brian Somers <brian@FreeBSD.org>
Date: Wed, 25 Aug 2010 18:09:52 +0000 (UTC)
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Subject: svn commit: r211818 - head/sys/kern
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Author: brian
Date: Wed Aug 25 18:09:51 2010
New Revision: 211818
URL: http://svn.freebsd.org/changeset/base/211818

Log:
  If we read zero bytes from the directory, early out with ENOENT
  rather than forging ahead and interpreting garbage buffer content
  and dirent structures.
  
  This change backs out r211684 which was essentially a no-op.
  
  MFC after:	1 week

Modified:
  head/sys/kern/vfs_default.c

Modified: head/sys/kern/vfs_default.c
==============================================================================
--- head/sys/kern/vfs_default.c	Wed Aug 25 16:23:50 2010	(r211817)
+++ head/sys/kern/vfs_default.c	Wed Aug 25 18:09:51 2010	(r211818)
@@ -281,9 +281,13 @@ get_next_dirent(struct vnode *vp, struct
 		if (error)
 			return (error);
 
-		*cpos = dirbuf;
-		*len = uio.uio_offset - *off;
 		*off = uio.uio_offset;
+
+		*cpos = dirbuf;
+		*len = (dirbuflen - uio.uio_resid);
+
+		if (*len == 0)
+			return (ENOENT);
 	}
 
 	dp = (struct dirent *)(*cpos);