netdev - Re: Sending undersized ARP packets with VXLAN L3 interface

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHA+R7Ok6K_9U6RCZkSLCuVXtFG4Zs60FQKFZMu-v2yK581hog@mail.gmail.com>
Date:	Wed, 27 Aug 2014 10:28:56 -0700
From:	Cong Wang <cwang@...pensource.com>
To:	Martin Rusko <martin.rusko@...il.com>
Cc:	netdev <netdev@...r.kernel.org>
Subject: Re: Sending undersized ARP packets with VXLAN L3 interface

On Wed, Aug 27, 2014 at 10:06 AM, Martin Rusko <martin.rusko@...il.com> wrote:
>
> I'm wondering, where is the proper place to fix this. Should
> arp_create() function allocate skb big enough to produce ethernet
> frame with at least minimum size? Or is it somewhere in NIC drivers
> where small packets are padded with zeros?

Drivers do that, for example e1000:

        /* On PCI/PCI-X HW, if packet size is less than ETH_ZLEN,
         * packets may get corrupted during padding by HW.
         * To WA this issue, pad all small packets manually.
         */
        if (skb->len < ETH_ZLEN) {
                if (skb_pad(skb, ETH_ZLEN - skb->len))
                        return NETDEV_TX_OK;
                skb->len = ETH_ZLEN;
                skb_set_tail_pointer(skb, ETH_ZLEN);
        }
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html