svn commit: r299460 - head/sbin/fsck_ffs

[Conrad E. Meyer]

Author: cem
Date: Wed May 11 16:20:23 2016
New Revision: 299460
URL: https://svnweb.freebsd.org/changeset/base/299460

Log:
  fsck_ffs: Don't overrun mount device buffer
  
  Maybe this case is impossible.  Either way, when attempting to "/dev/"-prefix a
  non-global device name, check that we do not overrun the f_mntfromname buffer.
  
  In this case, truncating (with strlcpy or similar) would not be useful, since
  the f_mntfromname result of getmntpt() is passed directly to open(2) later.
  
  Reported by:	Coverity
  CID:		1006789
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/sbin/fsck_ffs/main.c

Modified: head/sbin/fsck_ffs/main.c
==============================================================================
--- head/sbin/fsck_ffs/main.c	Wed May 11 16:05:32 2016	(r299459)
+++ head/sbin/fsck_ffs/main.c	Wed May 11 16:20:23 2016	(r299460)
@@ -644,6 +644,9 @@ getmntpt(const char *name)
 		statfsp = &mntbuf[i];
 		ddevname = statfsp->f_mntfromname;
 		if (*ddevname != '/') {
+			if (strlen(_PATH_DEV) + strlen(ddevname) + 1 >
+			    sizeof(statfsp->f_mntfromname))
+				continue;
 			strcpy(device, _PATH_DEV);
 			strcat(device, ddevname);
 			strcpy(statfsp->f_mntfromname, device);