Re: [net-2.6 PATCH] af_packet: move strict addr_len check right before dev_[mc/unicast]_[add/del]

[Jiri Pirko <jpirko-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

Wed, Mar 03, 2010 at 07:40:01AM CET, jpirko-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org wrote:
>Subject: [net-2.6 PATCH] af_packet: move strict addr_len check right before dev_[mc/unicast]_[add/del]

Dave please apply this against net-next-2.6. I see that 914c8ad2d18b is still not in
net-2.6.

Thanks a lot

Jirka

>
>My previous patch 914c8ad2d18b62ad1420f518c0cab0b0b90ab308 incorrectly changed
>the length check in packet_mc_add to be more strict. The problem is that
>userspace is not filling this field (and it stays zeroed) in case of setting
>PACKET_MR_PROMISC or PACKET_MR_ALLMULTI. So move the strict check to the point
>in path where the addr_len must be set correctly.
>
>Signed-off-by: Jiri Pirko <jpirko-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>
>diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
>index 031a5e6..1612d41 100644
>--- a/net/packet/af_packet.c
>+++ b/net/packet/af_packet.c
>@@ -1688,6 +1688,8 @@ static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
> {
> 	switch (i->type) {
> 	case PACKET_MR_MULTICAST:
>+		if (i->alen != dev->addr_len)
>+			return -EINVAL;
> 		if (what > 0)
> 			return dev_mc_add(dev, i->addr, i->alen, 0);
> 		else
>@@ -1700,6 +1702,8 @@ static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
> 		return dev_set_allmulti(dev, what);
> 		break;
> 	case PACKET_MR_UNICAST:
>+		if (i->alen != dev->addr_len)
>+			return -EINVAL;
> 		if (what > 0)
> 			return dev_unicast_add(dev, i->addr);
> 		else
>@@ -1734,7 +1738,7 @@ static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
> 		goto done;
> 
> 	err = -EINVAL;
>-	if (mreq->mr_alen != dev->addr_len)
>+	if (mreq->mr_alen > dev->addr_len)
> 		goto done;
> 
> 	err = -ENOBUFS;
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html