On 7 March 2014 11:56, Vegard Nossum <vegard.nossum@xxxxxxxxxx> wrote:
> Both the in-kernel and BSD strlcpy() require that the source string is
> NUL terminated. We could use strncpy() + explicitly terminate the result,
> but this relies on src and dest having the same size, so the safest thing
> to do seems to explicitly terminate the source string before doing the
> strlcpy().
>
> Fixes: f9a23c84486ed35 ("isdnloop: use strlcpy() instead of strcpy()")
> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
> ---
> drivers/isdn/isdnloop/isdnloop.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/isdn/isdnloop/isdnloop.c b/drivers/isdn/isdnloop/isdnloop.c
> index 02125e6..50cd348 100644
> --- a/drivers/isdn/isdnloop/isdnloop.c
> +++ b/drivers/isdn/isdnloop/isdnloop.c
> @@ -1070,6 +1070,14 @@ isdnloop_start(isdnloop_card *card, isdnloop_sdef *sdefp)
> return -EBUSY;
> if (copy_from_user((char *) &sdef, (char *) sdefp, sizeof(sdef)))
> return -EFAULT;
> +
> + /*
> + * Null terminate strings from userspace so we don't have to worry
> + * about this later on.
> + */
> + for (i = 0; i < 3; i++)
> + sdef.num[i][sizeof(sdef.num[0]) - 1] = '\0';
> +
> spin_lock_irqsave(&card->isdnloop_lock, flags);
> switch (sdef.ptype) {
> case ISDN_PTYPE_EURO:
Ping, Dave? Just making sure this doesn't fall through the cracks. I
don't see the patch applied anywhere yet and without this patch we
still have a valid security concern IMO.
Vegard
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