Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <ffaff797-0424-5aef-6ad7-d7e999f83198@paragon-software.com>
Date:   Fri, 28 Oct 2022 20:07:21 +0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.11.0
Subject: [PATCH 12/14] fs/ntfs3: Fix wrong if in hdr_first_de
Content-Language: en-US
From:   Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
To:     <ntfs3@lists.linux.dev>
CC:     <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>
References: <fc5957cc-a71b-cfa3-f291-cb63b23800d1@paragon-software.com>
In-Reply-To: <fc5957cc-a71b-cfa3-f291-cb63b23800d1@paragon-software.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

We need to check used bytes instead of total.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
---
  fs/ntfs3/ntfs.h | 5 +++--
  1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ntfs3/ntfs.h b/fs/ntfs3/ntfs.h
index 9f764bf4ed0a..86ea1826d099 100644
--- a/fs/ntfs3/ntfs.h
+++ b/fs/ntfs3/ntfs.h
@@ -714,12 +714,13 @@ static inline struct NTFS_DE *hdr_first_de(const struct INDEX_HDR *hdr)
  {
  	u32 de_off = le32_to_cpu(hdr->de_off);
  	u32 used = le32_to_cpu(hdr->used);
-	struct NTFS_DE *e = Add2Ptr(hdr, de_off);
+	struct NTFS_DE *e;
  	u16 esize;
  
-	if (de_off >= used || de_off >= le32_to_cpu(hdr->total))
+	if (de_off >= used || de_off + sizeof(struct NTFS_DE) > used )
  		return NULL;
  
+	e = Add2Ptr(hdr, de_off);
  	esize = le16_to_cpu(e->size);
  	if (esize < sizeof(struct NTFS_DE) || de_off + esize > used)
  		return NULL;
-- 
2.37.0