Re: [PATCH] cachefiles: fix dentry leak in cachefiles_open_file()

[Baokun Li]

On 2024/8/26 21:55, Markus Elfring wrote:

…

Add the missing dput() to cachefiles_open_file() for a quick fix.

I suggest to use a goto chain accordingly.


…

Hi Markus,


Thanks for the suggestion, but I think the current solution is simple
enough that we don't need to add a label to it.

Actually, at first I was going to release the reference count of the
dentry uniformly in cachefiles_look_up_object() and delete all dput()
in cachefiles_open_file(), but this may conflict when backporting
the code to stable. So just keep it simple to facilitate backporting
to stable.

Thanks,
Baokun

+++ b/fs/cachefiles/namei.c
@@ -554,6 +554,7 @@ static bool cachefiles_open_file(struct cachefiles_object 
*object,
        if (!cachefiles_mark_inode_in_use(object, d_inode(dentry))) {
                pr_notice("cachefiles: Inode already in use: %pd (B=%lx)\n",
                          dentry, d_inode(dentry)->i_ino);
+               dput(dentry);
                return false;

Please replace two statements by the statement “goto put_dentry;”.


…

error:
        cachefiles_do_unmark_inode_in_use(object, d_inode(dentry));

+put_dentry:

        dput(dentry);
        return false;
}

Regards,
Markus

--
With Best Regards,
Baokun Li