netdev - Re: [PATCH net] net: cdc_ncm: workaround for missing CDC Union

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: <2214944.HMNV73jJm5@linux-5eaq.site>
Date:	Mon, 21 Jan 2013 15:55:05 +0100
From:	Oliver Neukum <oneukum@...e.de>
To:	Bjørn Mork <bjorn@...k.no>
Cc:	Alexey Orishko <alexey.orishko@...il.com>, netdev@...r.kernel.org,
	linux-usb@...r.kernel.org, Greg Suarez <gsuarez@...thmicro.com>,
	Alexey Orishko <alexey.orishko@...ricsson.com>
Subject: Re: [PATCH net] net: cdc_ncm: workaround for missing CDC Union

On Monday 21 January 2013 15:47:13 Bjørn Mork wrote:
> But I wonder if this isn't really a generic problem in usbnet.  The
> FLAG_MULTI_PACKET test here seems completely bogus:
> 
>         if (length % dev->maxpacket == 0) {
>                 if (!(info->flags & FLAG_SEND_ZLP)) {
>                         if (!(info->flags & FLAG_MULTI_PACKET)) {
>                                 urb->transfer_buffer_length++;
>                                 if (skb_tailroom(skb)) {
>                                         skb->data[skb->len] = 0;
>                                         __skb_put(skb, 1);
>                                 }
>                         }
>                 } else
>                         urb->transfer_flags |= URB_ZERO_PACKET;
>         }
> 
> Either the FLAG_MULTI_PACKET minidriver will have already padded the
> buffer so that we do not hit (length % dev->maxpacket == 0), or we
> should choose one of the alternatives: ZLP or padding.

But we cannot simply call __skb_put for a complicated data frame.
Besides you may want the current behavior.

	Regards
		Oliver

--
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