1. Jan 03, 2018
    • John Fastabend's avatar
      net: ptr_ring: otherwise safe empty checks can overrun array bounds · bcecb4bb
      John Fastabend authored
      
      
      When running consumer and/or producer operations and empty checks in
      parallel its possible to have the empty check run past the end of the
      array. The scenario occurs when an empty check is run while
      __ptr_ring_discard_one() is in progress. Specifically after the
      consumer_head is incremented but before (consumer_head >= ring_size)
      check is made and the consumer head is zeroe'd.
      
      To resolve this, without having to rework how consumer/producer ops
      work on the array, simply add an extra dummy slot to the end of the
      array. Even if we did a rework to avoid the extra slot it looks
      like the normal case checks would suffer some so best to just
      allocate an extra pointer.
      
      Reported-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
      Fixes: c5ad119f
      
       ("net: sched: pfifo_fast use skb_array")
      Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bcecb4bb
  2. Dec 30, 2017
  3. Dec 29, 2017
  4. Dec 28, 2017