[PATCH -next] fs/ntfs3: Fix potential NULL/IS_ERR bug in ntfs_lookup()

[Peng Zhang]

From: ZhangPeng <zhangpeng362@xxxxxxxxxx>

Dan Carpenter reported a Smatch static checker warning:

fs/ntfs3/namei.c:96 ntfs_lookup()
error: potential NULL/IS_ERR bug 'inode'
It will cause null-ptr-deref when dir_search_u() returns NULL if the
file is not found.
Fix this by replacing IS_ERR() with IS_ERR_OR_NULL() to add a check for
NULL.

Fixes: fb6b59b5a2d6 ("fs/ntfs3: Fix null-ptr-deref on inode->i_op in ntfs_lookup()")
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
---
 fs/ntfs3/namei.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
index 3db34d5c03dc..f23c2c26dd08 100644
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -93,7 +93,7 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 	 * If the MFT record of ntfs inode is not a base record, inode->i_op can be NULL.
 	 * This causes null pointer dereference in d_splice_alias().
 	 */
-	if (!IS_ERR(inode) && inode->i_op == NULL) {
+	if (!IS_ERR_OR_NULL(inode) && inode->i_op == NULL) {
 		iput(inode);
 		inode = ERR_PTR(-EINVAL);
 	}
-- 
2.25.1