svn commit: r356722 - stable/12/sbin/fsck_msdosfs

[Xin LI]

Author: delphij
Date: Tue Jan 14 06:28:07 2020
New Revision: 356722
URL: https://svnweb.freebsd.org/changeset/base/356722

Log:
  MFC r356628: Require FAT to occupy at least one sector.

Modified:
  stable/12/sbin/fsck_msdosfs/boot.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sbin/fsck_msdosfs/boot.c
==============================================================================
--- stable/12/sbin/fsck_msdosfs/boot.c	Tue Jan 14 06:15:41 2020	(r356721)
+++ stable/12/sbin/fsck_msdosfs/boot.c	Tue Jan 14 06:28:07 2020	(r356722)
@@ -253,7 +253,7 @@ readboot(int dosfs, struct bootblock *boot)
 		boot->FATsecs = boot->bpbFATsmall;
 	}
 
-	if (boot->FATsecs > UINT32_MAX / boot->bpbFATs) {
+	if (boot->FATsecs < 1 || boot->FATsecs > UINT32_MAX / boot->bpbFATs) {
 		pfatal("Invalid FATs(%u) with FATsecs(%zu)",
 			boot->bpbFATs, (size_t)boot->FATsecs);
 		return FSFATAL;