svn commit: r301564 - head/sys/fs/nfsclient

[Conrad E. Meyer]

Author: cem
Date: Tue Jun  7 20:00:20 2016
New Revision: 301564
URL: https://svnweb.freebsd.org/changeset/base/301564

Log:
  nfs_clvfsops: Prevent strdup of stack garbage with bogus mount specs
  
  If strlen(hostp) was zero, the stack array 'nam' would never be initialized
  before being strdup()ed.  Fix this by initializing it to the empty string.
  
  It's possible some external condition makes this case impossible, in which
  case, an assertion instead of this workaround is appropriate.
  
  Introduced in r299848.
  
  Reported by:	Coverity
  CID:		1355336
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/sys/fs/nfsclient/nfs_clvfsops.c

Modified: head/sys/fs/nfsclient/nfs_clvfsops.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clvfsops.c	Tue Jun  7 19:49:08 2016	(r301563)
+++ head/sys/fs/nfsclient/nfs_clvfsops.c	Tue Jun  7 20:00:20 2016	(r301564)
@@ -806,7 +806,8 @@ nfs_mount_parse_from(struct vfsoptlist *
 		nam[len + offset++] = ':';
 		memmove(nam + len + offset, spec, speclen);
 		nam[len + speclen + offset] = '\0';
-	}
+	} else
+		nam[0] = '\0';
 
 	/*
 	 * XXX: IPv6