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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: ntfs3@lists.linux.dev, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH 2/3] fs/ntfs3: Potential NULL dereference in hdr_find_split()
Date: Tue, 24 Aug 2021 10:50:15 +0300	[thread overview]
Message-ID: <20210824075015.GB13096@kili> (raw)
In-Reply-To: <20210824074932.GA13096@kili>

The "e" pointer is dereferenced before it has been checked for NULL.
Move the dereference after the NULL check to prevent an Oops.

Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 fs/ntfs3/index.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
index 07d6dee0a4ba..489e0fffbc75 100644
--- a/fs/ntfs3/index.c
+++ b/fs/ntfs3/index.c
@@ -556,11 +556,12 @@ static const struct NTFS_DE *hdr_find_split(const struct INDEX_HDR *hdr)
 	size_t o;
 	const struct NTFS_DE *e = hdr_first_de(hdr);
 	u32 used_2 = le32_to_cpu(hdr->used) >> 1;
-	u16 esize = le16_to_cpu(e->size);
+	u16 esize;
 
 	if (!e || de_is_last(e))
 		return NULL;
 
+	esize = le16_to_cpu(e->size);
 	for (o = le32_to_cpu(hdr->de_off) + esize; o < used_2; o += esize) {
 		const struct NTFS_DE *p = e;
 
-- 
2.20.1


  reply	other threads:[~2021-08-24  7:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24  7:49 [PATCH 1/3] fs/ntfs3: Fix error code in indx_add_allocate() Dan Carpenter
2021-08-24  7:50 ` Dan Carpenter [this message]
2021-08-24  9:35   ` [PATCH 2/3] fs/ntfs3: Potential NULL dereference in hdr_find_split() Kari Argillander
2021-08-24  7:51 ` [PATCH 3/3] fs/ntfs3: Fix error handling in indx_insert_into_root() Dan Carpenter
2021-08-24 10:22   ` Kari Argillander
2021-08-27 17:47   ` Konstantin Komarov
2021-08-24  9:03 ` [PATCH 1/3] fs/ntfs3: Fix error code in indx_add_allocate() Kari Argillander

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