1. 28 Nov, 2013 1 commit
    • Eric Dumazet's avatar
      tcp: must unclone packets before mangling them · e5704e27
      Eric Dumazet authored
      [ Upstream commit c52e2421 ]
      
      TCP stack should make sure it owns skbs before mangling them.
      
      We had various crashes using bnx2x, and it turned out gso_size
      was cleared right before bnx2x driver was populating TC descriptor
      of the _previous_ packet send. TCP stack can sometime retransmit
      packets that are still in Qdisc.
      
      Of course we could make bnx2x driver more robust (using
      ACCESS_ONCE(shinfo->gso_size) for example), but the bug is TCP stack.
      
      We have identified two points where skb_unclone() was needed.
      
      This patch adds a WARN_ON_ONCE() to warn us if we missed another
      fix of this kind.
      
      Kudos to Neal for finding the root cause of this bug. Its visible
      using small MSS.
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
      e5704e27
  2. 26 Oct, 2013 39 commits