linux-kernel - Re: [PATCH] afs: proc cells and rootcell are writeable

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:	Tue, 28 Jan 2014 20:27:54 +0000
From:	Al Viro <viro@...IV.linux.org.uk>
To:	David Howells <dhowells@...hat.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-afs@...ts.infradead.org, Pali Roh??r <pali.rohar@...il.com>
Subject: Re: [PATCH] afs: proc cells and rootcell are writeable

On Tue, Jan 28, 2014 at 08:20:12PM +0000, David Howells wrote:
> Linus Torvalds <torvalds@...ux-foundation.org> wrote:
> 
> > > -       p = proc_create("cells", 0, proc_afs, &afs_proc_cells_fops);
> > > +       p = proc_create("cells", S_IFREG | S_IRUGO | S_IWUSR, proc_afs, &afs_proc_cells_fops);
> > > -       p = proc_create("rootcell", 0, proc_afs, &afs_proc_rootcell_fops);
> > > +       p = proc_create("rootcell", S_IFREG | S_IRUGO | S_IWUSR, proc_afs, &afs_proc_rootcell_fops);
> > 
> > So the S_IFREG isn't necessary.
> 
> True.  Is it worth creating proc_create_special() that can create a non-regular
> file and then making proc_create() only permit regular files (and complain if
> the S_IFMT field is not zero)?

We already do: in proc_create_data() we have
        struct proc_dir_entry *pde;
        if ((mode & S_IFMT) == 0)
                mode |= S_IFREG;

        if (!S_ISREG(mode)) {
                WARN_ON(1);     /* use proc_mkdir() */
                return NULL;
        }

proc_mkdir{,_data,_mode} are there for purpose.  Nobody had been insane
enough to put FIFOs or sockets in procfs and anything else would need
additional data anyway.  proc_symlink() is there, proc_mknod() isn't and
nobody has complained yet.  Let's keep it that way, plese...
--
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/