Eric Lee / smarc-ti-linux-kernel

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Commit 21ac2deb8e75eef817b0a3feeb6a0cef4745eba3

Authored by David Vrabel
Committed by Greg Kroah-Hartman
1 parent 7efe8f1bb7

xen-netfront: use correct linear area after linearizing an skb 

[ Upstream commit 11d3d2a16cc1f05c6ece69a4392e99efb85666a6 ]

Commit 97a6d1bb2b658ac85ed88205ccd1ab809899884d (xen-netfront: Fix
handling packets on compound pages with skb_linearize) attempted to
fix a problem where an skb that would have required too many slots
would be dropped causing TCP connections to stall.

However, it filled in the first slot using the original buffer and not
the new one and would use the wrong offset and grant access to the
wrong page.

Netback would notice the malformed request and stop all traffic on the
VIF, reporting:

    vif vif-3-0 vif3.0: txreq.offset: 85e, size: 4002, end: 6144
    vif vif-3-0 vif3.0: fatal error; disabling device

Reported-by: Anthony Wright <anthony@overnetdata.com>
Tested-by: Anthony Wright <anthony@overnetdata.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Showing 1 changed file with 3 additions and 0 deletions Side-by-side Diff

drivers/net/xen-netfront.c
Diff comments   View file @ 21ac2de
... ... @@ -627,6 +627,9 @@
627 627 slots, skb->len);
628 628 if (skb_linearize(skb))
629 629 goto drop;
  630 + data = skb->data;
  631 + offset = offset_in_page(data);
  632 + len = skb_headlen(skb);
630 633 }
631 634  
632 635 spin_lock_irqsave(&queue->tx_lock, flags);