This is a note to let you know that I've just added the patch titled

    ipheth: Properly distinguish length and alignment in URBs and skbs

to the 2.6.38-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipheth-properly-distinguish-length-and-alignment-in-urbs-and-skbs.patch
and it can be found in the queue-2.6.38 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 9c412942a0bb19ba18f7bd939d42eff1e132a901 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <[email protected]>
Date: Tue, 3 May 2011 07:49:25 +0000
Subject: ipheth: Properly distinguish length and alignment in URBs and skbs

From: Ben Hutchings <[email protected]>

commit 9c412942a0bb19ba18f7bd939d42eff1e132a901 upstream.

The USB protocol this driver implements appears to require 2 bytes of
padding in front of each received packet.  This used to be equal to
the value of NET_IP_ALIGN on x86, so the driver abused that constant
and mostly worked, but this is no longer the case.  The driver also
mixed up the URB and packet lengths, resulting in 2 bytes of junk at
the end of the skb.

Introduce a private constant for the 2 bytes of padding; fix this
confusion and check for the under-length case.

Signed-off-by: Ben Hutchings <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/net/usb/ipheth.c |   14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

--- a/drivers/net/usb/ipheth.c
+++ b/drivers/net/usb/ipheth.c
@@ -65,6 +65,7 @@
 #define IPHETH_USBINTF_PROTO    1
 
 #define IPHETH_BUF_SIZE         1516
+#define IPHETH_IP_ALIGN                2       /* padding at front of URB */
 #define IPHETH_TX_TIMEOUT       (5 * HZ)
 
 #define IPHETH_INTFNUM          2
@@ -202,18 +203,21 @@ static void ipheth_rcvbulk_callback(stru
                return;
        }
 
-       len = urb->actual_length;
-       buf = urb->transfer_buffer;
+       if (urb->actual_length <= IPHETH_IP_ALIGN) {
+               dev->net->stats.rx_length_errors++;
+               return;
+       }
+       len = urb->actual_length - IPHETH_IP_ALIGN;
+       buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
 
-       skb = dev_alloc_skb(NET_IP_ALIGN + len);
+       skb = dev_alloc_skb(len);
        if (!skb) {
                err("%s: dev_alloc_skb: -ENOMEM", __func__);
                dev->net->stats.rx_dropped++;
                return;
        }
 
-       skb_reserve(skb, NET_IP_ALIGN);
-       memcpy(skb_put(skb, len), buf + NET_IP_ALIGN, len - NET_IP_ALIGN);
+       memcpy(skb_put(skb, len), buf, len);
        skb->dev = dev->net;
        skb->protocol = eth_type_trans(skb, dev->net);
 


Patches currently in stable-queue which might be from [email protected] 
are

queue-2.6.38/ipheth-properly-distinguish-length-and-alignment-in-urbs-and-skbs.patch

_______________________________________________
stable mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/stable

Reply via email to