• Emil Goode's avatar
    usbnet: remove generic hard_header_len check · eb85569f
    Emil Goode authored
    This patch removes a generic hard_header_len check from the usbnet
    module that is causing dropped packages under certain circumstances
    for devices that send rx packets that cross urb boundaries.
    
    One example is the AX88772B which occasionally send rx packets that
    cross urb boundaries where the remaining partial packet is sent with
    no hardware header. When the buffer with a partial packet is of less
    number of octets than the value of hard_header_len the buffer is
    discarded by the usbnet module.
    
    With AX88772B this can be reproduced by using ping with a packet
    size between 1965-1976.
    
    The bug has been reported here:
    
    https://bugzilla.kernel.org/show_bug.cgi?id=29082
    
    This patch introduces the following changes:
    - Removes the generic hard_header_len check in the rx_complete
      function in the usbnet module.
    - Introduces a ETH_HLEN check for skbs that are not cloned from
      within a rx_fixup callback.
    - For safety a hard_header_len check is added to each rx_fixup
      callback function that could be affected by this change.
      These extra checks could possibly be removed by someone
      who has the hardware to test.
    - Removes a call to dev_kfree_skb_any() and instead utilizes the
      dev->done list to queue skbs for cleanup.
    
    The changes place full responsibility on the rx_fixup callback
    functions that clone skbs to only pass valid skbs to the
    usbnet_skb_return function.
    Signed-off-by: default avatarEmil Goode <emilgoode@gmail.com>
    Reported-by: default avatarIgor Gnatenko <i.gnatenko.brain@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    eb85569f
ax88179_178a.c 37.1 KB