• Julia Lawall's avatar
    pppol2tp: Remove null pointer dereference. · 5dc474d6
    Julia Lawall authored
    If session is NULL, it is not possible to access its name field.  So I
    have split apart the printing of the error message to drop the
    printing of the name field in this case.
    
    The macro PRINTK actually only evaluates its arguments starting with
    the third one if the bitwise conjunction of the first two is non-zero.
    Normally, this conjunction would only be non-zero if debugging mode
    were turned on, but when session is NULL, the first argument in both
    the old and new code is -1, and thus the bitwise conjunction is true.
    Perhaps a different strategy is desired, such as using tunnel->debug,
    which session->debug is initialized to, but tunnel can also be NULL,
    so this does not completely solve the problem.
    
    
    This problem was found using the following semantic match
    (http://www.emn.fr/x-info/coccinelle/)
    
    // <smpl>
    @@
    expression E, E1;
    identifier f;
    statement S1,S2,S3;
    @@
    
    * if (E == NULL)
    {
      ... when != if (E == NULL) S1 else S2
          when != E = E1
    * E->f
      ... when any
      return ...;
    }
    else S3
    // </smpl>
    Signed-off-by: default avatarJulia Lawall <julia@diku.dk>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    5dc474d6
pppol2tp.c 65.3 KB