svn commit: r281928 - head/lib/libmd

[Garrett Cooper]

Author: ngie
Date: Fri Apr 24 11:03:47 2015
New Revision: 281928
URL: https://svnweb.freebsd.org/changeset/base/281928

Log:
  Avoid an infinite loop by ensuring that the amount of bytes read is greater
  than 0 in MDXFileChunk when calculating the checksum
  
  This edgecase can be triggered if the file is truncated while the checksum
  is being calculated (i.e. the EOF is reached)
  
  Differential Revision: https://reviews.freebsd.org/D2351 (patch by darius)
  PR: 196694
  Reviewed by: delphij, ngie
  Submitted by: Daniel O'Connor <darius at dons.net.au>
  Sponsored by: EMC / Isilon Storage Division

Modified:
  head/lib/libmd/mdXhl.c

Modified: head/lib/libmd/mdXhl.c
==============================================================================
--- head/lib/libmd/mdXhl.c	Fri Apr 24 10:21:20 2015	(r281927)
+++ head/lib/libmd/mdXhl.c	Fri Apr 24 11:03:47 2015	(r281928)
@@ -74,7 +74,7 @@ MDXFileChunk(const char *filename, char 
 			i = read(f, buffer, sizeof(buffer));
 		else
 			i = read(f, buffer, n);
-		if (i < 0) 
+		if (i <= 0) 
 			break;
 		MDXUpdate(&ctx, buffer, i);
 		n -= i;