svn commit: r336755 - stable/11/sbin/fsck_msdosfs

[Xin LI]

Author: delphij
Date: Fri Jul 27 05:40:03 2018
New Revision: 336755
URL: https://svnweb.freebsd.org/changeset/base/336755

Log:
  MFC r336236: Detect and handle invalid number of FATs.

Modified:
  stable/11/sbin/fsck_msdosfs/boot.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sbin/fsck_msdosfs/boot.c
==============================================================================
--- stable/11/sbin/fsck_msdosfs/boot.c	Fri Jul 27 05:21:20 2018	(r336754)
+++ stable/11/sbin/fsck_msdosfs/boot.c	Fri Jul 27 05:40:03 2018	(r336755)
@@ -87,6 +87,10 @@ readboot(int dosfs, struct bootblock *boot)
 		pfatal("Invalid sector size: %u", boot->bpbBytesPerSec);
 		return FSFATAL;
 	}
+	if (boot->bpbFATs == 0) {
+		pfatal("Invalid number of FATs: %u", boot->bpbFATs);
+		return FSFATAL;
+	}
 	if (!boot->bpbRootDirEnts)
 		boot->flags |= FAT32;
 	if (boot->flags & FAT32) {