From mboxrd@z Thu Jan  1 00:00:00 1970
From: Kay Sievers <kay.sievers@vrfy.org>
Date: Sat, 29 Aug 2009 14:15:06 +0000
Subject: Re: [security] Race condition in udev
Message-Id: <ac3eb2510908290715p2207784dh56cc55873eedb03c@mail.gmail.com>
List-Id: <linux-hotplug.vger.kernel.org>
References: <20090821102407.GA29609@florz.florz.dyndns.org>
In-Reply-To: <20090821102407.GA29609@florz.florz.dyndns.org>
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To: linux-hotplug@vger.kernel.org

On Fri, Aug 28, 2009 at 19:34, Florian Zumbiehl<florz@florz.de> wrote:
>> below you find a patch that should fix the specific issue - I just am
>> not sure that it interacts nicely with the rest of udev. Also, I haven't
>> tried it, not even compiled it.
>
> here is another patch for basically the same problem in
> util_unlink_secure(), same disclaimer applies.
>
> Florian
>
> diff --git a/libudev/libudev-util-private.c b/libudev/libudev-util-private.c
> index 3641b36..28008c5 100644
> --- a/libudev/libudev-util-private.c
> +++ b/libudev/libudev-util-private.c
> @@ -102,6 +102,10 @@ int util_unlink_secure(struct udev *udev, const char *filename)
>  {
>        int retval;
>
> +       retval = chmod(filename, 0000);
> +       if (retval)
> +               err(udev, "chmod(%s, 0000) failed: %m\n", filename);
> +
>        retval = chown(filename, 0, 0);
>        if (retval)
>                err(udev, "chown(%s, 0, 0) failed: %m\n", filename);

We need only one chmod() here. I changed the order.

Thanks,
Kay