From: Namjae Jeon <linkinjeon@kernel.org>
Date: Wed, 24 May 2023 15:13:38 +0000 (+0900)
Subject: ksmbd: call putname after using the last component
X-Git-Tag: v6.6.17~4772^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6fe55c2799bc29624770c26f98ba7b06214f43e0;p=platform%2Fkernel%2Flinux-rpi.git

ksmbd: call putname after using the last component

last component point filename struct. Currently putname is called after
vfs_path_parent_lookup(). And then last component is used for
lookup_one_qstr_excl(). name in last component is freed by previous
calling putname(). And It cause file lookup failure when testing
generic/464 test of xfstest.

Fixes: 74d7970febf7 ("ksmbd: fix racy issue from using ->d_parent and ->d_name")
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 9bdb01c5b201..6f302919e9f7 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -86,12 +86,14 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
 	err = vfs_path_parent_lookup(filename, flags,
 				     &parent_path, &last, &type,
 				     root_share_path);
-	putname(filename);
-	if (err)
+	if (err) {
+		putname(filename);
 		return err;
+	}
 
 	if (unlikely(type != LAST_NORM)) {
 		path_put(&parent_path);
+		putname(filename);
 		return -ENOENT;
 	}
 
@@ -108,12 +110,14 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
 	path->dentry = d;
 	path->mnt = share_conf->vfs_path.mnt;
 	path_put(&parent_path);
+	putname(filename);
 
 	return 0;
 
 err_out:
 	inode_unlock(parent_path.dentry->d_inode);
 	path_put(&parent_path);
+	putname(filename);
 	return -ENOENT;
 }