[PATCH 2/6] smb/server: fix memory leak in ksmbd_vfs_set_durable_owner()

From: ZhangGuoDong <[email protected]>

See the procedure below:

  smb2_open
    ksmbd_vfs_set_durable_owner
      fp->owner.name = name

  // When the connection goes away
  ksmbd_sessions_deregister
    ksmbd_session_destroy
      ksmbd_destroy_file_table
        __close_file_table_ids
          session_fd_check // skip()
            ksmbd_vfs_set_durable_owner
              fp->owner.name = name // memory leak

Fixes: 0726814421c2 ("ksmbd: add SMB3 request replay support")
Signed-off-by: ZhangGuoDong <[email protected]>
Reviewed-by: ChenXiaoSong <[email protected]>
---
 fs/smb/server/vfs_cache.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c
index c28e3d65d64b..5acd06020d42 100644
--- a/fs/smb/server/vfs_cache.c
+++ b/fs/smb/server/vfs_cache.c
@@ -1655,7 +1655,7 @@ void ksmbd_stop_durable_scavenger(void)
 int ksmbd_vfs_set_durable_owner(struct ksmbd_file *fp,
 				struct ksmbd_user *user)
 {
-	char *name;
+	char *name, *old_name;
 
 	if (!user)
 		return -EINVAL;
@@ -1666,10 +1666,12 @@ int ksmbd_vfs_set_durable_owner(struct ksmbd_file *fp,
 		return -ENOMEM;
 
 	spin_lock(&fp->f_lock);
+	old_name = fp->owner.name;
 	fp->owner.uid = user->uid;
 	fp->owner.gid = user->gid;
 	fp->owner.name = name;
 	spin_unlock(&fp->f_lock);
+	kfree(old_name);
 
 	return 0;
 }
-- 
2.54.0