linux-kernel - Re: [PATCH 04/22][RFC] Unionfs: Common file operations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 1 Sep 2006 22:47:47 -0400
From:	Josef Sipek <jsipek@....cs.sunysb.edu>
To:	Trond Myklebust <trond.myklebust@....uio.no>
Cc:	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	hch@...radead.org, akpm@...l.org, viro@....linux.org.uk
Subject: Re: [PATCH 04/22][RFC] Unionfs: Common file operations

On Fri, Sep 01, 2006 at 06:20:00PM -0400, Trond Myklebust wrote:
> On Thu, 2006-08-31 at 21:41 -0400, Josef Sipek wrote:
...
> > +	for (bindex = bstart; bindex <= bend; bindex++) {
> > +		hidden_dentry = dtohd_index(file->f_dentry, bindex);
> > +		if (!hidden_dentry)
> > +			continue;
> > +
> > +		dget(hidden_dentry);
> > +		mntget(stohiddenmnt_index(inode->i_sb, bindex));
> > +		hidden_file = dentry_open(hidden_dentry,
> > +					stohiddenmnt_index(inode->i_sb, bindex),
> > +					file->f_flags);
> 
> Race! You cannot open an underlying NFS file by name after it has been
> looked up: you have no guarantee that it hasn't been renamed.

>From what I can see, the solution to this would be to pass the lookup
intents in unionfs_lookup down to the lower filesystem (the way it should be
done in the first place). Then, we could use the dentry here without any
problems. Is that all that needs to be done or am I forgetting something?

Thanks,

Josef "Jeff" Sipek.

-- 
VGER BF report: H 0
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/