From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>,
"Gong, Sishuai" <sishuai@purdue.edu>,
"jlbec@evilplan.org" <jlbec@evilplan.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] configfs: fix a race in configfs_lookup()
Date: Wed, 25 Aug 2021 07:29:00 +0200 [thread overview]
Message-ID: <20210825052900.GA26714@lst.de> (raw)
In-Reply-To: <YSXSyGliOy9BCLkj@zeniv-ca.linux.org.uk>
On Wed, Aug 25, 2021 at 05:19:04AM +0000, Al Viro wrote:
> On Mon, Aug 23, 2021 at 07:08:47PM +0200, Christoph Hellwig wrote:
>
> > We can't hold a spinlock over inode allocation. So it would have to be
> > something like this:
>
> Check for -ENAMETOOLONG first; easier for analysis that way.
Indeed.
> > + dentry->d_fsdata = configfs_get(sd);
> > + sd->s_dentry = dentry;
> > + spin_unlock(&configfs_dirent_lock);
> >
> > - found = 1;
> > - err = configfs_attach_attr(sd, dentry);
> > - break;
> > + inode = configfs_create(dentry, mode);
> > + if (IS_ERR(inode)) {
> > + configfs_put(sd);
> > + return ERR_CAST(inode);
>
> Er... Won't that leave dentry with dangling ->d_fsdata?
Yes. Existing problem, though.
next prev parent reply other threads:[~2021-08-25 5:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 21:44 [PATCH] configfs: fix a race in configfs_lookup() sishuaigong
2021-08-23 7:46 ` Christoph Hellwig
[not found] ` <AFABA8B1-0523-4F8C-A9DD-DDC5638DEAF7@purdue.edu>
2021-08-23 17:08 ` Christoph Hellwig
2021-08-23 19:07 ` Gong, Sishuai
2021-08-25 5:19 ` Al Viro
2021-08-25 5:29 ` Christoph Hellwig [this message]
[not found] <20210820213243.786-1-sishuai@purdue.edu>
2021-12-29 2:23 ` Gong, Sishuai
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