From: Miklos Szeredi <miklos@szeredi.hu>
To: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org,
Linux Security Module list
<linux-security-module@vger.kernel.org>
Subject: Re: [PATCH] vfs: allow unprivileged whiteout creation
Date: Tue, 5 May 2020 12:50:56 +0200 [thread overview]
Message-ID: <CAJfpegs3QbWa3gDGNv1atmanP_SE1KE3RhehQ7A+n_cNOa3Bsg@mail.gmail.com> (raw)
In-Reply-To: <CAFqZXNu8jsz_4eqgLOc8RGSSAWhiKc=YcByvoTiBeYUprT+kMw@mail.gmail.com>
On Fri, May 1, 2020 at 4:46 PM Ondrej Mosnacek <omosnace@redhat.com> wrote:
>
> On Fri, May 1, 2020 at 9:31 AM Miklos Szeredi <miklos@szeredi.hu> wrote:
> > --- a/fs/namei.c
> > +++ b/fs/namei.c
> > @@ -3505,12 +3505,14 @@ EXPORT_SYMBOL(user_path_create);
> >
> > int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
> > {
> > + bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV;
> > int error = may_create(dir, dentry);
> >
> > if (error)
> > return error;
> >
> > - if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
> > + if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD) &&
> > + !is_whiteout)
>
> Sorry for sidetracking, but !capable(CAP_MKNOD) needs to be last in
> the chain, otherwise you could get a bogus audit report of CAP_MKNOD
> being denied in case is_whiteout is true.
Thanks, fixed in the latest revision.
Miklos
next prev parent reply other threads:[~2020-05-05 10:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-09 21:28 [PATCH] vfs: allow unprivileged whiteout creation Miklos Szeredi
2020-05-01 4:14 ` Al Viro
2020-05-01 7:31 ` Miklos Szeredi
2020-05-01 14:46 ` Ondrej Mosnacek
2020-05-05 10:50 ` Miklos Szeredi [this message]
2020-05-01 18:39 ` Stephen Smalley
2020-05-04 11:18 ` Miklos Szeredi
2020-05-04 15:38 ` Stephen Smalley
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