cvs commit: src/sys/netinet

[Matthew Dillon]

dillon      2004/10/26 20:43:47 PDT

DragonFly src repository

  Modified files:
    sys/netinet          tcp_usrreq.c 
  Log:
  Fix a NULL pointer dereference panic that occurs when the TCP protocol
  stack races against userland while closing a tcp connection.  It is
  possible for userland to queue a disconnect request but for the protocol
  stack to then receive a packet that causes it to call tcp_drop()->tcp_close()
  which also disconnects the inpcb from the tcpcb.  When the protocol stack
  then processes the disconnect request it hits the panic because the inpcb
  no longer has a tcpcb connected to it.
  
  The bug generally only occured on SMP systems where the latency in intra-cpu
  communication opens up the window of opportunity for the bug to occur.
  
  Panic-Reported-by: Adam K Kirchhoff <adamk at xxxxxxxxxxxx>
  
  Revision  Changes    Path
  1.27      +11 -5     src/sys/netinet/tcp_usrreq.c


http://www.dragonflybsd.org/cvsweb/src/sys/netinet/tcp_usrreq.c.diff?r1=1.26&r2=1.27&f=u