Re: [PATCH v2 1/3] pppoatm: don't send frames to destroyed vcc

From: Krzysztof Mazur
Date: Tue Oct 30 2012 - 16:19:29 EST


On Tue, Oct 30, 2012 at 09:35:00AM +0000, David Woodhouse wrote:
> On Mon, 2012-10-22 at 19:14 +0200, Krzysztof Mazur wrote:
> > Now pppoatm_send(), like vcc_sendmsg(), checks for vcc flags that
> > indicate that vcc is not ready.
>
> I note that vcc_sendmsg() also checks for sock->state == SS_CONNECTED.
> Is that check not needed here? Otherwise, looks sane enough.
>
> Acked-By: David Woodhouse <David.Woodhouse@xxxxxxxxx>

I don't think so. We never leave SS_CONNECTED state. This check is
done in vcc_sendmsg() because it's called from userspace.

However maybe we should check socket state before assigning vcc to
pppoatm (untested):

diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
index 0dcb5dc..df06d14 100644
--- a/net/atm/pppoatm.c
+++ b/net/atm/pppoatm.c
@@ -414,6 +414,8 @@ static int pppoatm_ioctl(struct socket *sock, unsigned int cmd,
return -ENOIOCTLCMD;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
+ if (sock->state != SS_CONNECTED)
+ return -EINVAL;
return pppoatm_assign_vcc(atmvcc, argp);
}
case PPPIOCGCHAN:

Thanks.

Krzysiek
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