[PATCH 2/3] fs/ntfs3: Potential NULL dereference in hdr_find_split()

From: Dan Carpenter
Date: Tue Aug 24 2021 - 03:50:44 EST


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@xxxxxxxxxx>
---
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