Re: [2.6.0-test8/9] ethertap oops

Re: [2.6.0-test8/9] ethertap oops

[Andi Kleen]

Simon Roscic <simon.roscic@chello.at> writes:

> EIP is at ethertap_rx+0x131/0x2a0 [ethertap]

Does this patch fix it?

-Andi

diff -u linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o linux-2.6.0test7mm1-averell/drivers/net/ethertap.c
--- linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o	2003-09-11 04:12:33.000000000 +0200
+++ linux-2.6.0test7mm1-averell/drivers/net/ethertap.c	2003-10-26 23:41:17.000000000 +0100
@@ -302,11 +302,12 @@
 
 static void ethertap_rx(struct sock *sk, int len)
 {
-	struct net_device *dev = tap_map[sk->sk_protocol];
+	unsigned unit = sk->sk_protocol - NETLINK_TAPBASE; 
+	struct net_device *dev;
 	struct sk_buff *skb;
 
-	if (dev==NULL) {
-		printk(KERN_CRIT "ethertap: bad unit!\n");
+	if (unit >= max_taps || (dev = tap_map[unit]) == NULL) { 
+		printk(KERN_CRIT "ethertap: bad unit %u!\n", unit);
 		skb_queue_purge(&sk->sk_receive_queue);
 		return;
 	}
diff -u linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c-o linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c
--- linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c-o	2003-10-09 00:29:02.000000000 +0200
+++ linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c	2003-10-26 23:42:44.000000000 +0100
@@ -777,6 +777,7 @@
 	if (input)
 		nlk_sk(sk)->data_ready = input;
 
+	sk->sk_protocol = unit;
 	netlink_insert(sk, 0);
 	return sk;
 }

Re: [2.6.0-test8/9] ethertap oops

[David S. Miller]

On Sun, 26 Oct 2003 23:45:52 +0100
Andi Kleen <ak@muc.de> wrote:

> diff -u linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o linux-2.6.0test7mm1-averell/drivers/net/ethertap.c
> --- linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o	2003-09-11 04:12:33.000000000 +0200
> +++ linux-2.6.0test7mm1-averell/drivers/net/ethertap.c	2003-10-26 23:41:17.000000000 +0100

This part looks good, applied.

> diff -u linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c-o linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c
> --- linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c-o	2003-10-09 00:29:02.000000000 +0200
> +++ linux-2.6.0test7mm1-averell/net/netlink/af_netlink.c	2003-10-26 23:42:44.000000000 +0100
> @@ -777,6 +777,7 @@
>  	if (input)
>  		nlk_sk(sk)->data_ready = input;
>  
> +	sk->sk_protocol = unit;
>  	netlink_insert(sk, 0);
>  	return sk;
>  }

This part is not needed, netlink_create() does this for us :-)

Thanks Andi.

Re: [2.6.0-test8/9] ethertap oops

[David S. Miller]

On Mon, 27 Oct 2003 13:26:35 +0100
Andi Kleen <ak@suse.de> wrote:

> I don't know if it actually fixed the bug, I did not test it
> (sorry, should have stated that in the original mail)
> But at least it should printk now instead of crashing.

Ok, it's still an improvement over the blind dereferencing
it does not.

Re: [2.6.0-test8/9] ethertap oops

[Andi Kleen]

On Sun, Oct 26, 2003 at 11:48:28PM -0800, David S. Miller wrote:
> On Sun, 26 Oct 2003 23:45:52 +0100
> Andi Kleen <ak@muc.de> wrote:
> 
> > diff -u linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o linux-2.6.0test7mm1-averell/drivers/net/ethertap.c
> > --- linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o	2003-09-11 04:12:33.000000000 +0200
> > +++ linux-2.6.0test7mm1-averell/drivers/net/ethertap.c	2003-10-26 23:41:17.000000000 +0100
> 
> This part looks good, applied.

I don't know if it actually fixed the bug, I did not test it
(sorry, should have stated that in the original mail)
But at least it should printk now instead of crashing.

-Andi

Re: [2.6.0-test8/9] ethertap oops

[Simon Roscic]

On Monday, 27. Oct 2003 13:26, Andi Kleen wrote:
> On Sun, Oct 26, 2003 at 11:48:28PM -0800, David S. Miller wrote:
> > On Sun, 26 Oct 2003 23:45:52 +0100
> >
> > Andi Kleen <ak@muc.de> wrote:
> > > diff -u linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o
> > > linux-2.6.0test7mm1-averell/drivers/net/ethertap.c ---
> > > linux-2.6.0test7mm1-averell/drivers/net/ethertap.c-o	2003-09-11
> > > 04:12:33.000000000 +0200 +++
> > > linux-2.6.0test7mm1-averell/drivers/net/ethertap.c	2003-10-26
> > > 23:41:17.000000000 +0100
> >
> > This part looks good, applied.
>
> I don't know if it actually fixed the bug, I did not test it
> (sorry, should have stated that in the original mail)
> But at least it should printk now instead of crashing.
>
> -Andi

Hi Andi,

Your patch fixed the bug!  Thanks a lot!
I applyed the first hunk as David wrote above.

bye,
        simon.