From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: Karsten Keil <isdn@linux-pingi.de>,
netdev@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [patch] isdn: make sure strings are null terminated
Date: Thu, 24 Nov 2011 14:34:56 +0300 [thread overview]
Message-ID: <20111124113456.GI3258@mwanda> (raw)
In-Reply-To: <4ECCAE14.3070008@bfs.de>
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On Wed, Nov 23, 2011 at 09:25:56AM +0100, walter harms wrote:
>
>
> Am 23.11.2011 07:42, schrieb Dan Carpenter:
> > These strings come from the user. We strcpy() them inside
> > cf_command() so we should check that they are NULL terminated and
> > return an error if not.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >
> > diff --git a/drivers/isdn/divert/divert_procfs.c b/drivers/isdn/divert/divert_procfs.c
> > index 33ec9e4..0c16687 100644
> > --- a/drivers/isdn/divert/divert_procfs.c
> > +++ b/drivers/isdn/divert/divert_procfs.c
> > @@ -242,6 +242,10 @@ static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
> > case IIOCDOCFINT:
> > if (!divert_if.drv_to_name(dioctl.cf_ctrl.drvid))
> > return (-EINVAL); /* invalid driver */
> > + if (strlen(dioctl.cf_ctrl.msn) >= sizeof(dioctl.cf_ctrl.msn))
> > + return -EINVAL;
> > + if (strlen(dioctl.cf_ctrl.fwd_nr) >= sizeof(dioctl.cf_ctrl.fwd_nr))
> > + return -EINVAL;
>
> forcing the last field to be zero seems more easy.
> dioctl.cf_ctrl.fwd_nr[sizeof(dioctl.cf_ctrl.fwd_nr))-1]=0;
>
That's a valid option to use, but I'd prefer to return an error code
here because that's what we do on the line before. Passing a too
long string is clearly invalid.
regards,
dan carpenter
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next prev parent reply other threads:[~2011-11-24 11:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-23 6:42 [patch] isdn: make sure strings are null terminated Dan Carpenter
2011-11-23 7:03 ` Eric Dumazet
2011-11-23 7:16 ` Dan Carpenter
2011-11-24 12:41 ` [patch v2] " Dan Carpenter
2011-11-29 23:40 ` David Miller
2011-11-23 8:25 ` [patch] " walter harms
2011-11-24 11:34 ` Dan Carpenter [this message]
2011-11-24 12:21 ` walter harms
2011-11-24 12:30 ` David Laight
2011-11-24 13:17 ` Karsten Keil
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