cvs commit: src/sys/net if_clone.c

[Ruslan Ermilov]

ru          2005-11-24 18:56:14 UTC

  FreeBSD src repository

  Modified files:
    sys/net              if_clone.c 
  Log:
  Fix the following bugs:
  
  - In ifc_name2unit(), disallow leading zeroes in a unit.
  
    Exploit: ifconfig lo01 create
  
  - In ifc_name2unit(), properly handle overflows.  Otherwise,
    either of two local panic()'s can occur, either because
    no interface with such a name could be found after it was
    successfully created, or because the code will bogusly
    assume that it's a wildcard (unit < 0 due to overflow).
  
    Exploit: ifconfig lo<overflowed_integer> create
  
  - Previous revision made the following sequence trigger
    a KASSERT() failure in queue(3):
  
    Exploit: ifconfig lo0 destroy; ifconfig lo0 destroy
  
    This is because IFC_IFLIST_REMOVE() is always called
    before ifc->ifc_destroy() has been run, not accounting
    for the fact that the latter can fail and leave the
    interface operating (like is the case for "lo0").
    So we ended up calling LIST_REMOVE() twice.  We cannot
    defer IFC_IFLIST_REMOVE() until after a call to
    ifc->ifc_destroy() because the ifnet may have been
    removed and its memory has been freed, so recover from
    this by re-inserting the ifnet in the cloned interfaces
    list if ifc->ifc_destroy() indicates a failure.
  
  Revision  Changes    Path
  1.9       +20 -5     src/sys/net/if_clone.c