From ecda7a75d9b7f2f8ed56a1d108faf90d3a813642 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 24 Aug 2021 10:50:15 +0300 Subject: [PATCH] fs/ntfs3: Potential NULL dereference in hdr_find_split() 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 Reviewed-by: Kari Argillander Signed-off-by: Konstantin Komarov --- 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 5fb41c9c89100..f4729aa50671f 100644 --- a/fs/ntfs3/index.c +++ b/fs/ntfs3/index.c @@ -557,11 +557,12 @@ 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;