From 56580f3f6d0ef8e9ae73160f4eea5d6d22d711b3 Mon Sep 17 00:00:00 2001
From: Xin LI <delphij@FreeBSD.org>
Date: Thu, 14 Dec 2017 07:55:11 +0000
Subject: [PATCH] MFC r326391: Prevent OOB access on corrupted msdos
 directories.

Submitted by:	Veo Zhang <veo live com>
---
 sbin/fsck_msdosfs/dir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sbin/fsck_msdosfs/dir.c b/sbin/fsck_msdosfs/dir.c
index 8e7fe4d29a03..20910216af28 100644
--- a/sbin/fsck_msdosfs/dir.c
+++ b/sbin/fsck_msdosfs/dir.c
@@ -619,7 +619,7 @@ readDosDirSection(int f, struct bootblock *boot, struct fatEntry *fat,
 			dirent.name[8] = '\0';
 			for (k = 7; k >= 0 && dirent.name[k] == ' '; k--)
 				dirent.name[k] = '\0';
-			if (dirent.name[k] != '\0')
+			if (k < 0 || dirent.name[k] != '\0')
 				k++;
 			if (dirent.name[0] == SLOT_E5)
 				dirent.name[0] = 0xe5;